In the early 90s, I needed a cheap driver once and almost bought an older Cadillac with this engine from a flipper (here in south Florida, low mileage cars like this from the elderly are all over). I asked him if the HT4100 was reliable (this was pre Internet, and I had no experience with it) and he thought for a second and said "it is not - this one works fine, but it won't for long, if I'm being honest". I was stunned and grateful.

@The_R-n-I_Guy

2 жыл бұрын

Wow, an honest car salesman?!?! There might be 10-15 in the entire country

@Johnny-so5xv

Жыл бұрын

I had a gold eldorado with this motor it drank 2 litres of coolant aday

@Shadow_Banned_Conservative

9 ай бұрын

I bought an 85 Cadillac Seville with this engine back in the early 2000s as a spare car to keep at my parent's home so I could fly to visit instead of driving 10 hrs each way to see them. I got it for $1500 from a work colleague when his grandmother passed away. It had receipts for a rebuild on both the engine and trans less than 10k miles before I bought it. I drove it several times when I visited, then gave it to my best friend's mother when she needed a car. It lasted about six months before a rod came through the side of the block. It was a smooth engine and it got excellent fuel economy. On my drive across the CA and AZ desert in the summer, with the A/C cranked it got me close to 40 mpg. It was very comfortable and even though it was slow, was an excellent cruiser at speed.

@Titanic19127

3 ай бұрын

How about the HT4500?

@empireOfLove2

Ай бұрын

@@Titanic19127 The 4.5 and 4.9 liter v8s that were built on this platform fixed a lot of the problems that the 4100 suffered from due to a rushed launch. The 4.9 ultimately morphed into the Northstar V8 that's well known as a good engine.

I thank GM from the bottom of my heart, these engines provided this old mechanic with probably a million dollars of revenue over the years, there was a period of about 5 years where they are pretty much all I worked on

@111000100101001

2 жыл бұрын

Same here, we would do a complete rebuild and upgrade when one was brought in on the hook.

@shanelucas3159

Жыл бұрын

I'm working on my 84 Fleetwood at the moment. I've lost track of how many weekends I've spent doing the water pump, radiator removal, and now the intake manifold gasket project. There's always something to do on this car. These cars should have came factory with a complimentary shop manual. As the second owner of mine, I'm trying to take good care of it.

@chuckmaddison2924

Жыл бұрын

I know the feeling. I have said, " I love people that drive European cars, coz we can charge like a wounded bull to fix." Same result $$$$$$$

@MrJoeltrain

Жыл бұрын

What's up with the melted looking valve covers I've seen on some later models I think probably 4.9? Look horrible.

@mark_osborne

Жыл бұрын

@@MrJoeltrain GM put a heavy black plastic sort of paint over the aluminum and it came loose giving it that "melted" look - yes horrible and no way to really fix it other than to scrape off the loose parts and attempt a re-paint

As a heavy line mechanic for Cadillac in the 1980s, I worked on several of these HT4100 engines. The most common issues with customer cars with this engine were oil leaks, mostly intake manifold. Also, overheating and warped blocks. Worth noting, the crankshaft flange only had 3 Torx screws that secured the flex plate to the crankshaft🤣. Also, this engine had such low vacuum that it wasn't enough to run the vacuum accessories of the car. So GM put a belt driven vacuum pump in with the other accessories in front of the engine (what a joke!). Cadillac should have kept the Olds Rocket 350 for these cars through the 80s!! The best engines Cadillac ever had were the 472 and 500 V8s. Honorable mention is the 425 and 368 derivatives of the 472....

@mcqueenfanman

2 жыл бұрын

Yep, an updated Olds 350with tbi or port injection would have been a great choice. Atleast they had the 307 to put in the big cars.

@djnmemphis10

Жыл бұрын

I have an 84 cadillac biarritz coupe and I want to swap out the engine for something more reliable and with more power. I'm trying to have race car or muscle car. Just more power

@JohnK-ph3vw

Жыл бұрын

@@mcqueenfanman I had an olds 307 in my 85 Lesabre. It was reliable, got about 25mpg on the highway. But it was a slowwwwww engine in comparison the even the 305.

@mcqueenfanman

Жыл бұрын

@@JohnK-ph3vw It had a cam that had all the torque in by 2,000 rpms. The H.O. 307 was much more livelier.

@chrispompano

Жыл бұрын

@DjnMemphis10 - Be sure to follow this very famous guys build. He's a wealthy Texan car-guy, Matt Garrett & very well resourced & funded. People compare him to a mini-Jay Leno. He has a great website & see his KZread build that he plans on swapping an Olds 406. Titled: - "1985 Cadillac Eldorado Biarritz convertible . "Pre engine swap to 6.6 Liter Oldsmobile 403" - I'd post the link, but my post could get deleted.

I remember even in the first few weeks and months after these terrible engines came out in the 1982 model year, coming across numerous 4100 engines and especially bare engine blocks in scrapyards, Not wrecking yards where parts are salvaged, but actual metal recycling SCRAPYARDS.

Although I spent the first 13 years of my career as a mechanic at a Ford dealership (1983-1996), I did occasionally work on other makes of cars. Usually something taken in on trade by the used car department. One of those times came when they had taken a Caddy in on trade with a seized 4100 engine. It was a beautiful car owned by a reality company that was used to haul prospective buyers around town to look at property. Somehow, no one ever changed the oil. At 59,000 miles the engine locked up. So they traded it in on a Lincoln Town Car. The used car manager asked me to get it running. We got a replacement engine from a local wrecking yard. It wasn't terribly difficult to swap, but I could never get the damn thing to idle properly. The internet wasn't widely available then, so repair information on that engine was hard to come by. I tried all the tricks I would use on a Ford with poor idle quality. I ended up swapping the TBI off the old engine which seemed to fix it. I guess the ECM didn't play well with strangers.

I never was a big fan of GM, but they played a big part in my life. They had a wiring plant in my hometown, and my uncle worked there for 20+ years, from the mid ‘70s on. He passed away recently at 75.

You are really pumping out lots of wonderful, long, videos. You're now at the top of my list. Thank you for your time and please keep them coming.

When I graduated from college in 1986, I bought a 1983 Coupe DeVille with this engine. It didn’t have much power but it was so smooth and quiet. I absolutely loved that car. Unfortunately, less than a year after I bought it, I was hit by an F-150 at a high rate of speed. The car was totaled. I replaced it with a new 1988 Chevy Corsica.

@handledeehandledum

2 жыл бұрын

Interesting - did you ever look back from the Chevy? Some of the basic engineering was in each GM. So apart from trim and early on engines, after about 65 the base problems/issues were often in every brand.

@Thundarr995

Жыл бұрын

My uncle bought a brand new Corsica back then. The paint started falling off in sheets. It wasn't even paid off yet. He took it back to the dealership thinking that they'd at least repaint it. They said no, there was nothing they could do for him. Well he was/is a really good artist. He went to the art store and bought some paint that could be easily cleaned off the windows. He painted big lemons on the windows and parked it on the street right in front of the dealership. After about a week the dealership agreed to repaint it.

Honestly, I think this engine and the reputation it earned- for being a grenade and a total slug in terms of performance- was the biggest straw that broke the Cadillac back. The Cimarron was a disaster, sure, but the 4.1 ruined what would've otherwise been great '82-'85 Cadillacs. I think it turned off a lot of buyers who happily left and went to Lincoln... which ironically had a 302 that wasn't much more powerful than the 4100. As shown by the Brougham that ran into '92 (albeit with the Olds 307 in '86 and the Chevy motors in '90), the cars themselves were great and honestly hold up very well even now 30+ years later. In particular, I feel the '80 redesign for the Coupe DeVille produced one of the most handsome cars of the era, but unfortunately any year aside from the 1980 is saddled with poor engines. I can't blame shoppers in the early 80s for shunning these cars, no matter how good they looked or how comfortable they are. The 4100 should have been held off until the downsized cars arrived for 1985- by then the engines had sorted through a lot of problems. I think the Chevy 305 or even Olds 307 would have been a much better option during this time after the V8-6-4 was deemed unacceptable. Even limiting cars to the 4.1 V6 or even the 3.8 probably would've hurt their reputation less. That being said, the 4100 did become what I would consider a good motor in the 4.5 and 4.9, which are nice to drive and have a much better reputation.

@sasz2107

2 жыл бұрын

I don't know that switching over to another division's engines would have gone over well. They were already using the 4.1 L Buick V6 and the Olds diesel 350. The 307 or the 305 were really the only V8 options. In 1977 Oldsmobile got into so much trouble for putting Chevy 350s into the Delta 88s. If Cadillac put a Chevrolet engine into their cars - that would not have gone over well. I do remember in the 80s a lot of people switching over to Lincoln because they were not happy with theri Cadillacs.

@Sedan57Chevy

2 жыл бұрын

@@sasz2107 a good engine from another division would've been better than a terrible Cadillac motor.

@donreinke5863

2 жыл бұрын

The 302 powered Lincoln Town Car would (and did) run rings around the 2 ton Fleetwood Brougham with that lame 250ci "4100" Ive driven both. The later 4.5 and 4.9 (pre Northstar junk) Cadillac engines were better.

@ralphl7643

2 жыл бұрын

They could have stayed with a normal 368 and a higher differential gear, but they wanted lower weight immediately. Why they didn't start developing 4 or 5 speed auto transmissions after the '73 oil crisis is another question.

@Sedan57Chevy

2 жыл бұрын

@@ralphl7643 I've heard it said that that the 368 had emissions issues on top of the lack of economy, so even with the 4-speed auto I don't know if it would've been an option. Still, I wonder if going to fuel injection would've been enough to get them a few more years. The 368 was a great engine.

It's always refreshing to be able to listen to someone with real knowledge on a subject, wax poetic on the character both good and bad on a love-hate platform. I've always wondered about how Cadillac people felt about the HT4100 and now I know! I'll look for a 4.5 or 4.9 Deville.

I had an 83 Fleetwood with that engine, and I beat the hell out of that car. It leaked everything, had a throw-out bearing holding tension for water pump/alternator and other junk. It lived, never overheated, and ran fine. I graduated to a 4.9 93 DeVille, and after 2 transmissions, I happily saw I drive away to get parted out. I still have a 6.0 368 V8-6-4 in an 81 Fleetwood, still running but of course, cylinder deactivation is permanently deleted.

@willythewave

2 жыл бұрын

A throwout bearing?

@donreinke5863

2 жыл бұрын

We swapped in a 500 out of a 75 Cadillac in an 81 Fleetwood when the V8-6-4 of course blew up. That car seemed like it would never stop accelerating, it was still building speed long after the 85 mph speedo had pegged.

@alb12345672

2 жыл бұрын

Pretty sad that GM to this day has problems with that cyl deactivation :lol:. My neighbor has it in his truck and it is a nightmare. He said he had a used caddy with it years ago, his fault for not learning a lesson.

@willythewave

2 жыл бұрын

@@donreinke5863 lol I bet that was fun. :)

@MR..181

Ай бұрын

😂should have overfilled those transmissions ?

"The party arrives when you do" -- love that! Another very informative overview. Thank you, sir.

This kind of video is exactly what i like on this channel. We all can basically agree that this motor is NOT good at all. But still, some people love these year Cadillacs and want to buy one. So instead of just badmouthing it to death, it's better to help the lovers/owners of these cars know how to preserve them to minimize damage and issues. Please do a video on the onboard diagnostics. It would be well worth your time.

@donreinke5863

2 жыл бұрын

If you like the car, swap in a later 4.9 Cadillac engine, by that time they had most of the bugs worked out, and the 4.9 at least produced reasonable power.

@klwthe3rd

2 жыл бұрын

@@donreinke5863 That idea sounds good in theory but the cost is not feasible.

@donreinke5863

2 жыл бұрын

@@klwthe3rd LOL THAT all depends on your capabilities and knowing where to get stuff for the right price. I once converted a 1981 Fleetwood Brougham from the worthless variable displacement 8-6-4 368 to a 500 ci engine scrounged from a 1975 Coupe de Ville. Actually an easy swap. When finished, that car seemed like it would never stop accelerating, easily burying the 85 mph speedometer.

@mixtecobajo5582

2 жыл бұрын

@@donreinke5863 What do you think about installing a Remanufactured 4.1L ? And if you upgrade to a 4.5 or 4.9, would you have to upgrade the transmission as well to compensate torque?? Thank you 🌅

@donreinke5863

2 жыл бұрын

@@mixtecobajo5582 The 4.1 had too many inherent problems for me to think about doing that. These engines were notorious for having piston slap issues (Cadillac called it a "bell knock" and at one time provided a kit to dealers to repair it) They were also well known for head gasket leaks, and GM actually recommended sealant (GM cooling system supplement) be added to the engine coolant to address that problem. Almost every transmission made for the last 50 years has upgrade parts available through the rebuilders supply distributors such as Transtar and WIT, as well as online sites, and its always a good idea to use upgraded transmission parts for greater durability, especially when installing a larger or more powerful engine.

The diagnostic system was amazing....all the code resets and real time data....plus the sequence to clear it all out....is great...once you learn how to do it. A lifesaver

The 4.5 was ok, the 4.9 was great! I had a 93 De Ville 4.9. Great gas mileage, a hot rod for performance. a pleasure to drive. Car had a few troubles, no internal engine problems. Trans gave trouble, gas mileage dropped from 28 mpg average to 20. Traded it off at 245K miles in '05 for a new Le Sabre. Another great car!

@immikeurnot

2 жыл бұрын

4.1/4.5/4.9 all leaked oil no matter what you tried to stop them. Iron heads with aluminum block is just a dumb choice, too.

@LowEnd31st

4 ай бұрын

I really liked the 4.5 the best. The 4.9 had too many fuel injector problems, which I experienced on 2 Seville’s which was a nightmare. 4.5 with TBI was the sweet spot for reliability

The growth in the channel is fantastic - well done Adam! Great “Porch Chat” as always. Another classic engine!

Years ago I worked for a firm on Atlanta's south side, whose fleet colors were Dove Gray. We had a Cadillac hearse from 1986. I do not recall who did the coachwork. Anyway it had a 4100 in it. We just hated it, not so much for lack of dependability, more for the lame power output. That engine combined with the weight of a Fleetwood 75 chassis and specialized coach work was completely overwhelmed. I really enjoy your in-depth reviews and knowledge. Thank you!

@jamespkuzman

2 жыл бұрын

When a hearse driver bemoans the lack of power, you know it’s bad!

I love these longer videos, the tranquil setting is wonderful too. Thank you so much.

My uncle was a transmission specialist in the late 80s up to early 2000s for Cadillac, he sold me a 1986 sedan DeVille he had rebuilt the transmission and probably maintenanced at the dealer in late 2000 and the car ran smooth as butter for having the 4.1v8

Your knowledge is amazing. Are you an automotive engineer/exec or grow up with a parent who was an auto exec? My Aunt Helen and Uncle Mit traded in their 77 Electra Limited for an 84 Coupe Deville. It was to be their retirement treat. Less than a year later they got rid of it and went back to Buick. It was a shame because the Deville was really an attractive car.

The 4100 which I had in an 82 Cadillac Eldorado was underpowered and used to ping when under load or going up a hill. The transmission would over rev and then buck to go from first gear to second. Yes, I do not remember ever going over 85 mph in this car. When I first bought it, all the sensors were clogged and had to be replaced. It wouldn't go over 65 mph and the engine had low miles on it. My favorite of all times was the water hoses that were channeled around the electronic ignition system. Someone didnt' hook them up tightly enough and one fell off its fiting and dumped gallons of coolant right on the electroncs. Killing it instantly .

Your knowledge of these cars is why this channel is exploding. Experts are hard to find. I really enjoy the calm demeanor and well presented material. Thanks.

I cannot tell you how thrilled I am to find this video that you have made! I’m seriously considering purchasing a 1986 Cadillac Sedan Deville Limousine Hess and Eisenhart

Thank you so much for this video! This was the most comprehensive summary of the issues plaguing those of us who owned 4.1 Cadillacs. I had an 85 Sedan deVille just like the one you pictured and I absolutely loved the car as a whole. It was smooth, very quiet and extremely pleasant to drive. My 4.1 had been rebuilt before I got it, but I did have issues: 1. I suddenly lost the oil pump while driving. Fortunately I was on a quiet residential space and I shut it off within 5 seconds of the oil light going on. I towed the car back to my house and dropped the pan, what had happened was one of the large steel pins that the pump gears ran on had slowly worked downward, allowing the shaft to disengage from the distributor. I bought a new Cadillac oil pump at the dealer, it was an updated pump from the 4.5. This issue made me lose trust in the car. 2. It was very sensitive to plug wire condition. Once the wires started to go bad it would slam into a lower gear very harshly, at first making me think that the trans had gone south. I drove out to a very dark place at night and watched sparks go all over the wires. I replaced them and the problem went away, only to reappear maybe a year later. New wires again solved the problem. 3. My 4.1 and many others I heard had a dull thumping sound in the engine. Somewhere I read or was told that it was camshaft end play. I don't know, but it sounded bad. 4. My thermostat went bad twice. Not bad enough to overheat and turn the light on, but when I parked and shut it off I could hear coolant boiling. I kept the coolant fresh and used the tabs. This was promptly repaired on both occasions.

You did hit on something there about rushing to and fro. I don't understand people in Audis/BMWs etc going really fast on the public roads. Indeed the party doesn't start until 'you' get there. Enjoy the ride. Feel the 'Corinthian' leather. Listen to the quality stereo. Oh no ... I arrived perhaps 2 1/2 minutes later ... but had a truly grand time getting there. Gimme a Jag/Cad/Linc from the 'era' and someone else can pound the lateral g 's and wind up to 6000 rpms if they really must.

@isaakwelch3451

Жыл бұрын

Corinthian leather was a Chrysler marketing scheme

I enjoy your videos. Your patience and Mr. Roger's way of describing some of these nightmares makes me worry about my mental health since I've had some of these junks and thought they'd be better off in the bottom of a lake.

I am absolutely astounded at your knowledge. Killing time watching a lot of your videos tonight and you are an encyclopedia. Bravo.

@RareClassicCars

Жыл бұрын

Thx!

Your videos are at the top of my watch list when I go to you tube. Great information coming to us without fan fare or fluff. Keep up the great work, Adam.

That was a nice summary of the 4100. Brought back some memories, like the Off/Warmer self -diagnostic feature. Thanks for the video.

Adam, you have a great thing with these videos. Such interesting conversations that so many of us can appreciate. Your experience speaks volumes (pun!) and all these videos don’t necessarily need to be road tests.kind of a fireside chat of sorts. Glad these are doing well for you. I find them wonderfully comprehensive. Thanks

Hey Adam, I have a friend that had a Seville with the 4100 in it & he had nothing but trouble with it. Thanks for another interesting chat!! 👍👍

As a 1991 Cadillac Deville owner I love these videos, I agree with you about the 4.9 engine, it's great! I'm planing to change the water pump this summer by myself. Not looking forward to it. :/

The secret to keeping the Ht 4100 going was the vegetable tabs. The original owners had them maintained by dealerships who knew about frequently changing the coolant, and added the tabs. When the cars were traded in, and became affordable for the second owners, they knew nothing about it, though there is a sticker under the hood about them which few people probably didn't read. So now coolant gets changed, MAYBE, but no tabs are added. Its the beginning of the end for those engines. Also frequent oil changes every 3000 miles helped greatly. My 83 Eldorado has never failed on me. It has 178.000 miles now, still runs fine. These cars are beautiful in and out, and drive nice and are SOOO COMFORTABLE!! I understand that these engines are available by rebuild companies who supposedly made upgrades to make them much more reliable.

@SauerkrautX

Жыл бұрын

What are vegetable tabs? I'm looking at an 85 Fleetwood with 80k miles on it and I want to make sure I can make it last. Also, how often should you change the coolant?

@chrispompano

Жыл бұрын

SEE MY COMMENTS ABOVE & HERE: ........about my comment below on using Evans NPG+ Waterless Coolant. It is recommended to run a 0 or low PSI radiator cap. That should help stop pressure induced head gasket leaks/coolant leaks in a system that runs high pressure......... I bet Evans NPG+ Waterless coolantwould be a blessing for these motors, with one of the new generation leave-in Kevlar or other technology Stop Leak formulas (only as a leave-in if compatible with Evans coolant) or a flush & permanant sealer, & reflush a 180F or maybe 160F thermostat, oxalic acid "wood bleach" coolant flush (carefully, or use POWDERED TIDE or Cascade Professional Fryer Boil Out), & neutralize it with Arm & Hammer Washing Soda, (this was the old 2 part GM flush by Prestone AS100...... GM TSB 99-06-02-012D & long-discontinued Prestone AS100 aka GM 12346500 was a 2-part canister ). I would even be using stuff like the well known AT-205 Re-Seal in the oil, & I wonder if that TRIBOTEX ceramic additive who's always a sponsor on Motor Head TV, would protect the cam....... Additives & Preservative for the HT-4100, was all started with GM's wood cellulous based stop leak tabs by Prestone!!!!! Old parts counter HT-4100 joke: Take 6 Tabs & don't call back in the morning! LoL! Or follow procedure in the JalopyJournal thread titled "RADIATOR FLUSH CEMICALS QUESTION??". The GM TSB was also used in over-dose treatment of the TABS to flush it out when it started to clogg-up the entire system!

@paulbohl3958

Жыл бұрын

Wow man! thanks for your input. I just found a 40,000 miles eldorado in excellent condition, but I’ve been so disheartened with everything I’ve been reading online about them so far. For a while I’ve been thinking I got a lemon. I don’t know if the previous owner put pellets in it so I’m going to get it flushed and add some in just incase. I saw that label near the radiator and it made me wonder if that’s why people had so much trouble with these

@philippeemami7594

8 ай бұрын

Thanks for your comments, really helpful. You mentioned rebuild companies who supposedly make upgrades to make the HT4100 much more reliable. Do you have any company name? Btw I own a 1982 Fleetwood Brougham with 84K miles and am pretty happy so far. I really love the car but am scared with everything I’ve been reading online about the HT4100. Does it worth to rebuild the engine or to swap it with a V8 350 Chevy??

@AJStone100k

7 ай бұрын

Yeah I learned the easy way. Did my water pump on a 93 DeVille. Keep fizzing out the pump no matter what. Went to GM the next day spent 17.99 or whatever the price for those tab's(Bars stop leak copper will work too)and never had a issue again. I drove that thing from Mississippi to Maryland in 08. Sold it to some kid in 09 for 500$. Still was going strong. Gave the SRTs hell around that time too 4s and 8s.

Found your video on the Aurora and now I am subscribed and eating up your videos. Appreciate your perspectives and that fact that you are cementing this automotive history online, especially the interviews with former designers and such! Bravo!!

@RareClassicCars

Жыл бұрын

Welcome aboard!

My GF bought a 1983 Cadilac Burritz in 1989. We knew, at the time, how crappy the 4100 engine was. You are exactly correct about the different metals used in the build. It leaked everything. I told Peggy before she bought that car to get an extra warranty on the engine and the dealer said sure. I think the car had about 50,000 miles when she bought it. After 9 months of ownership and all sorts of electrical issues the engine finally gave up. The dealer replaced the engine at a cost of $5000 (for them) and I think the salesman was fired for selling the warranty with the car. It was a beautiful car with a stainless steel roof. But, otherwise was a POS. Peg purchased a Jeep after that ordeal. Caddy had problems with other engine arrangements too. The 8-6-4 as another POS but likely due to early crude electronics. I'm retired now and have built several engines in the last 14 months. 454, 428CJ, 283, 350, 351, and a 502 and would love to get a 632 but at $30K I suppose I will wait on that one.

You have a very pleasant way of conveying an impressive knowledge of these cars. Keep it up, the channel will no doubt do very well.

This was informative. I look forward to the video about the 4.5 and 4.9 liter V8 which were derived from the HT 4100. It is interesting what you learn. The odd thing is other GM cars had V6's and V8's that were more reliable and had more power. I used to see the HT4100 badge on so many Cadillacs back in the day. Thank you for the video.

@trickyricky12147

4 ай бұрын

I believe the 1993 Cadillac Fleetwood was a full size platform RWD equipped with a 350 TBI. If I remember correctly. That's a Cadillac I'd go for from the same era, but has a much more dependable power train. Plus, knowing this I couldn't deal with the HT 4100 in smaller Cadillacs. Anything else I'd go for a FWD 1994 Cadillac Sedan Deville with the well-improved 4.9L. No Northstar junk for me 👎

@OLDS98

4 ай бұрын

@@trickyricky12147 Understood and agreed. At one point the Fleetwood with the 350 V8 was the most reliable Cadillac outside of the 4.5 and 4.9 liter V8 which was much improved. The 1992 Seville and Eldorado used the 4.9. The 1989-1994 Deville used the 4.5 and 4.9. The 1989-1992 Fleetwood and Sixty Special used the 4.5 and 4.9. It was 1993 and up that was the Northstar era. I know the 1994 Deville used the 4.9. It is sad there were some great looking cars in the 1990's at Cadillac but offered a unreliable powertrain.

@trickyricky12147

4 ай бұрын

@@OLDS98 Exactly. It is unfortunate because that had some of the most nice looking old school style Cadillacs in the 90s, but the unreliable engine (especially the early HT4100, but luckily the 4.5L and 4.9L were much better until the dreaded northstar came along. Ugh

@OLDS98

4 ай бұрын

@@trickyricky12147 They had a lot of nice looking Cadillacs and the 4.5 and 4.9 helped things a lot and then the Northstar came along. I think it impacted Cadillac more than we will ever know.

My grandparents had an '88 Sedan DeVille.. The car was garage kept and looked show room floor new. It had the 4.5 V8. As a kid, i remember the beautiful red leather interior. It was always serviced by the dealership. I remember the dealership would put some sort of tablets to put in the radiator every 3,000 miles. This was Cadillac's way of fixing the problem with blowing head gaskets. My granddad didn't catch it in time to save the engine. It only had 110,000 miles on it when it was scrapped.

I worked in a Cadillac only dealer in the late 1980s. We had fair size room in the parts department full of these engines. Always felt sorry for longtime Cadillac owners stuck with these…probably rarely had to deal with major engine issues in decades past.

Great video & backdrop Adam! Really interesting. I remember a friend's parents bought a new 85 DeVille & had frustrating problems with it but God knows how they drove or maintained the poor car. If I remember they traded it in a year or so later for an Olds 98 Regency with the 3.8V6. Years later in the late 90's I purchased a used 92 Coupe de Ville with the 4.9V8 and just loved the engine & the car. As you mentioned it was not quite as smooth idling all the time that you would think a Cadillac should have been. Did not remember that until you mentioned it. Look forward to more on these engines! Cheers

I just joined your channel but have REALLY enjoyed catching up on all your videos. I completely agree with your opinions regarding the Cadillac 4100, 4.5 and 4.9. In recent years I've owned an 88 Eldorado with the 4.5 and it really was a decent car. I think I had to replace the intake gasket, but that was the only major problem I can recall. Then I had a 91 DeVille with the 4.9 and it was a super nice engine. A failed water pump ( which, yes, was a huge PITA to replace) and fuel injectors were the only major issues. So the 4100 really did develop into a couple of decent engines, especially when you consider the dark years of the early 1980's. Nowadays I stick to my '69 DeVille with a bulletproof 472 and TH400 setup. Thanks for the cool videos and good channel. Regards, Matt.

I am a big fan of the information and trivia you provided in your videos. Thank you

Great stuff. Can't wait for vids on the 4.5 and HVAC OBD! Had a '90 DeVill that I adored and gave me no trouble.

We made a lot of money selling used GM motors of the 80s 😂😂 I also drove more than my share of these cars at some point. Cars that were traded in with bad motors, we bought from wholesalers and repaired, then one of us drove them until sold. A lot of really nice Caddies. But they were terrible engines for those that had no means to repair. I also recall GM had a bounty on these for trade in while under warranty..... Or was that the really bad 4-6-8? Oh, and every 4100/4500 got new water pumps, not rebuilt, on every install. Used engine, sure, but do not do all that labor without replacing with a new pump.

Geeze a top speed of 88! Was on I-10 recently and traffic was moving at 90. A clappped out Camry with body parts literally flapping in the wind blew by me at over 100.

You’ve carved out an interesting niche for yourself. You really deserve more subscribers. How did you learn all this info. Very impressive.

My dad had a 1985 Sedan DeVille, exactly like the one Adam pictured. The engine suffered the dreaded demise complete with oil and coolant mixing, even though the car had few miles and Dad drove it gingery. He had the engine rebuilt and drove the car uneventfully until about 2004. I had a 1991 Seville. No engine problems but I remember it vibrated significantly, which I thought surprising for a Cadillac. Also remember adding the coolant pellets and the prominently placed engine sticker instructing you to do so.

I find this content fascinating for some reason

Another great video. Now we all understand a bit more about engines like this. Could you make a video about GM management ? The good and the bad decisions that were made within the corporate structure. Thank you.

I worked at a Caddy dealer 84-86. Had a front row seat to all the disasters. HT, 4-6-8, and the diesel.

For GM's Flagship Line, Cadillac had some pretty crappy engines after 1981

I was horrified when these appeared in 1982, literally half the displacement of what had been under the hood not that many years before. The Hardly There 4100. For two different loyal Cadillac-buying friends this was the last stop. One bought an XJ6 the next time around, and the other a Cressida, and neither has ever gone back.

@V8_screw_electric_cars

2 жыл бұрын

Jaguar was 4.2 and had power of the 8.2, british even put it in some armored car, can't beat good engineering.

@melrose9252

2 жыл бұрын

Jaguars were horribly unreliable.

@V8_screw_electric_cars

2 жыл бұрын

@@melrose9252 Engines were good

Love your information, as I hopefully look for a classic for myself, your information is telling to avoid certain models and years thank you.

You are so very expert on these 4100... I too owned 4 of these--- a lot problems with 3 of them--- being that the 85 Eldorado convertible is actually 250 pounds heavier than the others, the strain on the 4100 engine was even greater. I did buy two used "recycled" engines since two of my 4100's developed death rattles....I did own one '83 roadster model that ran, without major issues (and with the original transmission) for 317,000 miles... and yes, I drove it as if I had an egg between the accelerator pedal and my foot! Really appreciate your expertise.

This garbage engine is one of my passions. I had a 1985 Deville which was the first year of the transverse mounted 4100. Mine had 150k miles on it when I had it/sold it (I didn't own it for long I maybe put 3k on it). It was somehow the original engine, numbers matching. I didn't have any problems specifically with the engine, it used maybe a quart of oil every 1000 miles or so. I made maybe 19mpg combined out of that car which I thought was really good for such a barge. It was pretty slow for sure, but honestly it kept up with traffic and had no trouble keeping 75 mph. The engine was smooth and quiet, and had a nice sound to it to me. But the engineering story of this engine pisses me off so badly that I really enjoy retelling it with the lens of it being a perfect example of why you give your engineers the time to really do a good job and don't focus on making arbitrary deadlines. Fucking your customers with a shitty product will do you worse than the short bump in cash will net you.

The biggest problem with the 4100? Galvanic electrolysis. The heads are good, the cranks are good(I’ve personally ground several hundred 4100 series cranks) but the blocks are junk( 4.1 RWD especially). I have seen perfectly good looking main cap and head bolt bosses shed their threads like a snake shedding its skin. 4.1 RWD blocks are prone to cracking on the rear main bulkhead. The 4.5 and 4.9 engines are both better than the 4.1. In fact, the 4.9 block weighs nearly twice as much as a 4.1 block.

Great video! I currently have an 85 Eldorado with the HT4100 engine. They do run smoothly and get good gas mileage. It's definitely not a performance engine.

@ericheld4382

2 жыл бұрын

Hi Greg.

@gregdelagrange8573

2 жыл бұрын

@@ericheld4382 Hey Eric. Check out my KZread channel. I've got some videos you might like.

@codywilt6158

2 жыл бұрын

I was going to look at an Eldorado with that Same engine here soon do you recommend the engine and how has it treated you?

@gregdelagrange8573

2 жыл бұрын

@@codywilt6158 That engine isn't the best by most standards but if it has been maintained properly and the car well cared for and in nice shape they're not bad.

@willg.5168

Жыл бұрын

I found a cherry '87 short body DeVille with a 4100 in it @165,xxx miles. Im sooooo curious as to wonder what was done to it to have reached those miles(rebuild, maintenance, etc). They started out asking 5500, but now its down to 3995. If it creeps down to about the 3500 mark, i just may get it at least for the body/interior. I can always replace the motor, right?

Like these talks, Adam! Liked the police officer story too; gave me a chuckle! Please keep these videos coming!👍😉😊

In the early 90’s, I inherited a very low mileage 83 Fleetwood Brougham that had an HT4100 lump. You’re too kind to this turd of an engine. Some engines, like 1st gen Northstar V8’s, had issues (head gaskets) but also had positives (when running well, the Northstar was a lovely engine that made great noises and excellent power). The HT4100 had nearly every problem imaginable, with almost no pluses. Yes, when working right it was smooth. It was also painfully underpowered, and in my case, with just 17,000 miles, almost never ran right. After pulling the engine, cracking it open and finding that it needed: gaskets top to bottom, crankshaft, camshaft, oil pump, a new intake manifold and a bunch of other nonsense, I gave the car to a friend, sans engine. He ended up dropping an LT1 in it (along with a 4L60e transmission), which transformed the car from a undrivable leaking slug, to quite a sleeper. I, however, didn’t have the time or skill for such surgery, so I was glad to see the car get a second life with a vastly superior drivetrain. Basically, the core problem with the 4100 is it was very badly made. Everything about it was Swiss cheese. At the time, GM was the largest industrial concern on the planet - they knew better than to ship garbage like the 4100, but they didn’t care enough to make sure it was built right. These weren’t design problems, these were casting issues, material quality verification problems, lack of attention to detail. People talk about the L62 (8-6-4), but that engine could be made reliable with disconnection of a single wire. The 4100 was, beyond any doubt in my head, the worst, most brand equity destroying engine in GM’s history.

I appreciate your commentaries, and how you name names as well

My dad had an 87 coupe de ville with this engine and we drove it from Los Angeles to Queens NYC back in 2003. The car was misfiring from the start and would struggle going up the Colorado mountains. It also almost left us stranded in the middle of nowhere on route 66. Craziest road trip of my life.

In the early 90s I worked at a machine shop and we specialized in the “HT” series engines. I liked doing a complete engine rebuild job on the rear wheel drive Caddys but hated the FWD ones, especially the oil cooler lines. It was one trying day that a 4.5 convinced me to go back to school for engineering and get out from under these things:)

This car was my Father's pride and joy. Ours too as kids. I was around 10 years old when we bought it used. 1982 Gold Cadillac coupe DeVille. I can remember it like yesterday. We were coming home from a long trip, we were about a half hour away from home. Then bam the engine was knocking and threw a rod. The engine was dead. We were towed all the way home. My Dad kept it in the garage for a year, then sold the body for cheap. I loved that car

I am a professional mechanic with 39 years of experience behind me and an ASE master certification….in heavy trucks. When it comes to cars, I know just enough to get me by. So imagine my frustration 20 years ago when someone sold my 75 year old widowed mother, living on social security, a Caddy with this godforsaken engine. You know the story; the guy was saving it for his pastor, but he felt my Mom deserved the car. He took my mother “hook line and sinker” The only thing this car did well was set still in park. And it didn’t even do that very well because it leaked oil when it was parked. My mom has no money but she loved the car and thought the guy was an angel for selling it to her instead of his pastor. I wanted to find the guy and beat him with rusted mining equipment for playing my mother, but I was too busy working on the Caddy with all my free time. About $2000 of my own money tied up in working on the Caddy, I convinced my Mom to sell it. She took a loss on it but I used her money and my own to buy her a ‘96 Taurus which turned out to be a much nicer car. She drove that without any problems until she passed.

Your presentations are among the very best.

My mother bought a 1989 C body Cadillac in 1990 - I learned how to drive in it and also how to work on cars- Looking forward to your video on the 4.5L engine - lots of memories of that car as it reached end of life around 2000

Love your videos! I agree, when those engines were right they ran very smoothly. They certainly had issues. Dealer techs made a good living keeping them going. Same with the Northstar, better engine but still a money maker. Miss those days!

I bought a triple white 82 DeVille with an HT4100 showing 100k for $800 last fall. Not running, it had been in storage since 1999. It got new tires in 99 and only has a few thousand miles more than listed on the tire receipt I found. So, I am thinking it developed problems at that time. I plan on a 6.0/4L80e swap. The car is super straight and solid.

@mixtecobajo5582

2 жыл бұрын

@Dan Duncombe, what do you think about installing a Remanufactured 4.1L engine to 86 Deville? Thanks🏅

After hearing that your car had the crankshaft and other items replaced at 25,000 miles, I was horrified but not surprised. Your tale of this engine fully reinforces my hatred for GM that goes back 40 years.

I am really enjoying your videos. At around 3:30 you talk about lack of performance and just settling into the right lane at your own pace. Problem is, most likely they will settle into the left lane.

Drove my 85 Eldorado 4100 from Erie to Atlanta. Smooth at 85. It's my daily driver. You're right about the smoothness. I pointed it out to my wife. No shake or pull. I also have an 84 Sedan Deville with the 4.1. Yes, it is slow, but I drive like a real luxury car. As you said, the party doesn't begin until it shows up! Balboa Blue, Balboa Blue vinyl top, original paint. She's a head turner.

Love this channel, keep up the good work!

Great job on this video. Your critique was outstanding on this motor

My Father had purchased a new 84 Fleetwood Brougham with the HT-4100 V8. As a business owner he would travel quite a bit; he had the car until 1992. The 84 had clocked 186000 miles! No issues at all! Just regular maintenance. The A/C and other electronic equipment worked well, right up to the day, it was left at the dealer in 1992. I saw the car and met the new owner who, had the car repainted (same color) and he said it was a nice smooth hwy cruiser . In fact when it was about a year old. I was able to get it up to just over 100 miles in hour!

You have a soothing way of telling a story. New fan but love your videos. You have awesome hair too!

@RareClassicCars

2 жыл бұрын

Ha. Thx!

Love the Porch and Field Chats Adam....wow you just know so much I Love it. I currently own a 1990 Cadillac Brougham and thank God it has the Chevy 5.7 350 Engine. Pretty much bullet proof Engine, much better than the ones you have been profiling. I cant believe how bad the Caddy Engines were for a while, so sad for the Standard of the World. Thank God today Caddy is back on track and back building the best cars in the world. Thanks for your videos Adam and incredible Knowledge. !!!!

@zlinedavid

2 жыл бұрын

Either you had a 1991, or someone swapped it over. 88-90 Broughams used the Oldsmobile 307. In 1991, they used the Chevy 305 TBI (easy 5.7 swap).

I used to go to auto auctions growing up, helping my dad check out cars to potential buy. Lots of HT4100 Caddys at the auctions at the time. We almost always avoided them. We didn't want to deal with upset customers with 4100 problems. We stayed far away from the 4-6-8 cars too. We actually liked the 5.7 diesel Caddys, Olds, Buicks, etc. Had more than a few as the family car, never had issues with any of ours but we were diesel people. I would LOVE to have a diesel Delta 88 today. Such a comfy cruiser of a boat, love the feel & styling.

@isaakwelch3451

Жыл бұрын

Once GM fixed the diesels in 81 they were quite good. But by that time the damage was done.

Thanks for thos review. I did not realize how slow those engines were. I liked your references to Bose and easy driving.

I worked for funeral home in 1984 and they bought a new limousine it was a 4 door with jump seats. They sent me to pick the car from the dealer. And l had to check the engine , l was shocked when I saw the ht 4100 .the car did have a. 3.73 rear end .but fully loaded with people it was working really hard to maintain 60mph.

April 2024 I bought an absolutely pristine light yellow with light tan interior, with 47,100 miles showing on the 1984 Cadillac Eldorado Biarritz odometer. Because I did not exercise "due diligence" and research before taking it for a test drive I drove it away with a huge smile on my face. I've driven it only a couple of times and each time I have other motorists give me the THUMBS UP, they smile and they watch it drive by with a smile on their face. I've had other motorists when pulling up next to me at a traffic light roll down their window and comment on how nice the car looks, they ask "How does it ride?" and they have other very positive comments to say. I am happy I own this beautiful car and I hope I might be lucky enough to enjoy many, many trouble free miles ahead. No, it is not my daily driver. I am retired and plan to drive this car only in fair weather, perhaps take it to local shows because it truly is an amazingly wonderfully showy car. It defines the last of the classic Cadillac's.

In the Fall of ‘86 I inherited an ‘85 “G” platform Pontiac Bonneville as a company car. It had a V-8 (I believe either the 267 or 305 and a 4-speed automatic). I almost got into a wreck trying to pass a car when I first drove it. At 60 mph it wouldn’t even downshift into passing gear. Having grown up during the muscle car era, I just couldn’t believe how anemic V-8s had become. Fortunately, I quickly transitioned into a new 1st Gen Mercury Sable with a V-6. It was like night and day in performance, handling, and interior ergonomics.

You sir....are loved and respected... thank you for you!!

I found this interesting. I would like to see one about those diag modes, maybe as part of an overall series of how diags could be done pre-OBD II, sometimes without special tools. I have a Chrysler K car, and you do the "key dance", ignition key on-off-on-off-on and count the flashes on the Check Engine light. I had a 92 Buick Century, and I had a reader that I vaguely remember. I think you had to look at combinations of lights on its little display. And when you mentioned oil leaks at around 9:00, I like the stock photo you used for an oil leak.

Wow definite flashbacks especially when you were talking about the onboard diagnostics. I had A few early 90’s Deville’s

Please do the electronic engine diagnostic video! Most shops these days don't even know how. I have a random Service Engine Light that comes and goes that I hope I can solve with some of your knowledge. Thanks so much for the valuable info.

This video does a great job of pointing out the cascading failures Cadillac had in the '80s that the division never really recovered from, which irrevocably eroded Cadillac's reputation: - Engine sharing among the divisions led to the disastrous problems caused by the Olds diesel. Cadillac should have been insulated from this, but they jumped right into it just like the other divisions. I remember at the time Cadillac owners being really ticked off that they were no longer getting Cadillac engines, but instead were getting Olds and Chevy engines that they were paying twice as much for. - Poorly tested features like the bolt-on V8-6-4 system led to reliability problems that again should not have occurred on Cadillacs. - When Caddy did get a new engine like the 4.1, it became immediately clear that Caddy no longer had the will or the way to properly test engines to ensure their customers were in good hands when they drove a car off the lot.

Those injector dropout tests are great. My '88 5.0 Mustang (with an '89 MAF computer) can do that too.

1986, just back to the US from my first overseas tour in the USAF bought a 1984 Eldorado Birritz, Silver with a red leather interior. Car was slow and smooth but held up well here in the LA basen. Thanks!

Fyi, Rainman Ray did a replacement of the ignition control on an early 2000s GM 90 degree 4.3 V6 today and it is an extremely similar module. I kind of wanted him to mention that having an ignition control underneath the distributor is a questionable engineering decision.

First Engine i ever rebuilt was a HT4100 with 50,000 1984 Seville. The old-timer gave me the car when he passed on. And it still sits in my storage building with around 125,000 on it so i can say my rebuild lasted and the owner took care it. My plan is to freshen it up in the next year or so. Keeping Fluids changed and freshly makes all the difference

@mixtecobajo5582

2 жыл бұрын

@AJ, do you suggest installing a Remanufactured or Rebuilt 4.1L on a 86 Deville?? And pros or cons for each ? Thank you🌅

@AJmx2702001

2 жыл бұрын

@@mixtecobajo5582 If you can find a reman for the right price go for it . Since the way things are now with supply issues getting the right parts a rebuilt could be hard to get or not exist . Most good remans come with some short term warranty. I am lucky to have access to Machine shop with unlimited capabilities.

I remember seeing so many 80’s Cadillacs come into the shop I worked at as a youngster with catastrophic engine failure. People basically ran these poor engines till they destroyed themselves. I remember seeing them with a lot of engine sludge with the valve covers off. I don’t remember one HT4100 V8 that had really good care from its owners.

I would watch a few of your videos on cars that i grew up admiring, but these porch talks have me looking for the next video...

Great video, please make one about the onboard diagnostics. Thanks Adam.

This channel is sweet , hope it grows

Have had the 4,5 for almost 8 years. Yes, its mileage and output were poor and it needed fresh coolant every 1-2 years. But I have no issues with it all the time when it was 10-17 years old.

Great and interesting video Paul

Ahh.... The 4100...as a tech at a gm dealership, these were so fun.. distributor gears failing, rod knock on #1 main, gm had a kit where you more or less put a oversize bearing in to compensate for wear. Seals failing on cylinder sleeves and getting coolant leaks...the list goes on. We were never short for work with these around

0-60 in 17 seconds is too slow to be called slow. Speaking about that water pump installation, sounds like the engineer behind that was German. Fortunately it appears he's gone back there

@danr1920

2 жыл бұрын

My '76 Astre took 21.

@kevinbarry71

2 жыл бұрын

@@danr1920 wow,

Thanx for very interesting information videos!Are you going to talk about the Cadillac Northstar?My brother had two of these with blown head gaskets, apart from that it seems to have been good engines.Thanx again for good videos.

i avoided this video for a long time sence i figured it would be someone who had no idea about the engine just shitting on it. how i was wrong. i have a 1985 deville and this is super usefull info. thanks! also ive binged alot of your videos now and i do prefer the tranquil setting

@RareClassicCars

Жыл бұрын

Ha. Thx!