My uncle had the 1979 Cutlass diesel 261 and it ran fine for years. I often drove it. He had added a more complex water separating system added at day one of owning this car as you mentioned water in truck diesel was a major destroyer of this engine. The second thing was the need to change oil on very short intervals. You did not need to use very exotic oil, just a good detergent oil. He changed the oil every 1,500 miles and never more than 2,000. It lasted years without any issue and he sold it in 1983. I drove it and got 30 mpg. My V-6 powered 1979 GM full size was sluggish and slow compared to this car which had good throttle response and was faster than a 6 cylinder car of the day. Yes compared to the last GM diesel this one had lots of issues but they could be minimized if you were in the know about the damage water in the fuel did to the injectors and you were really into maintenance.

I ordered a Cutlass in 1983 with the 4.3L V6 and drove the car for about 20 years, by the time I sent it to the junkyard the car had about 275,000 miles. It weighed 3,400 lbs, so was not the fastest, but once up to highway speed it ran fine at 30 mpg+ with the highest being 36. In the lighter Cierra it was higher mpg. I did add a good water separator to it. My brother had an 82 Cierra 4.3L he drove for years. I currently have an 84 Cierra diesel that came from Arizona so the body is solid. Another thing under development was the Tuned Induction V6 diesel. Tests reported 0-60 in Ten Seconds and quarter mile of 17.5 seconds which is faster then stock 4.3's. They reported 101 hp vs the stock 85 hp.

I know someone who had an 82 celebrity with a well worn iron duke , another friend had a 84 with a diesel, they sounded the same at idle.

People make fun of GM for trying to turn a gas engine into a diesel. However the fact is that most companies that make both gas and diesel engines will try to reuse as many parts between them as possible. Also I read somewhere that GM thought they had a new process that would have made the engine strong enough w/o adding more head bolts, but in practice it didn't work the way they thought it would. I think in reality the olds diesels were just another example of 80's GM forcing their customers to beta test their products.

Hey Adam, it's nice that you picked this very nice tranquil setting to talk about the notorious Oldsmobile diesel engine that has such a horrible reputation!!! Thanks for sharing this informative video!!! 👍👍🙂

I made a mound of money repairing the diesel injection pumps on 5.7 and 4.3 O’diesels. In late 70s through 84 when there were lots of them on the road and GM covered the pumps. I worked at a Chev and then Buick dealer. The diesel pump shop charged too much so the GM brands in the town sent them to me. My service manager and the IRS loved me those years. The elastomer damper ring that took shock out of the drive to governor weight cage would harden and fragment and then the bits plugged up ports and they quit. I did loads of engine repairs too but that was not as lucrative as injection pumps removed, fixed, and installed in a little over 1 1/2 hours for a little over 4 hours pay.

I still have three of these cars. Only one still runs. My nephew still drives the 82 Buick Century. It gets 32-36mpg and is extremely comfortable to ride in. The 4.3L V6 is not the worst diesel ever made; it just inherited its big brother's reputation. The V6 was a well built engine. All the problems of its big brother (350 olds diesel) had been fixed by the time it went into production--Good fuel filters, 4 bolt mains, 16 head bolts on a V6 instead the 10 on the V8, heavier block. One of the cars I have has 375,000 miles it and it never had anything done to it other than basic fuilds and filter changes. If the injectors had been replaced at least once in that time, it probably would still be going strong. The heads melted because of VERY wornout injectors. The biggest reason these didn't have morepower than they did is because the EGR valve was right in the middle of the intake and it only had less than an inch clearence all the way around it and they were governor limited to 3100rpm. I removed the EGR on the 82 and cut out the mount, and it was a big improvement in power. The biggest problem with these engines now is parts availiabilty. These would have been an amazing engine with a turbo.

Chevrolet Vega...

In 1980 I bought a VW Dasher wagon diesel and a buddy of mine bought an Olds Cutlass diesel wagon. I got nothing but bashing on how slow small and everything else compared to his Olds diesel , I drove his Olds several times and began to wonder if I didn't make the right choice on a diesel wagon over the Olds. This bashing went on for a couple years till one morning his wife took out of their drive way up a fairly steep hill and the Olds pitched a rod through the side of the block at 60,000 mi. My VW went on to surpass 200K miles and I received no more VW bashing out of my friend after the big explosion. Also by then the reputation was so bad he didn't even bother to put a new engine in the car to fix it. It went to the junk yard.

The Detroit automobile diesel engines of the '80s were a godsend to the Japanese manufacturers.

I was a tech at the only GM dealership in Canada that sold all GM models: Chev, Pontiac, Olds, Buick, Cadillac, Corvette, LD trucks, MD trucks, HD trucks. Eventuelly ran our HD truck garage and we worked on all these powerplants. We found that the blocks themselves didnt have the strength to withstand the compression pressures and we suffered with these diesel powerplants until the 6.2/6.5 which were true diesel blocks, with apprpriate lower block strength. Great channel, thanks for your on-going effort.

I bought a used 1978 Cutlass diesel from a co-worker for like $250 about 25 years ago. I got it cheap because it had two head bolts that broke at the cap. It was the 350 ci. I replaced the head gasket and the head bolts and the two batteries and drove it for a few months back and forth to work. Sometimes at a stop, the engine would just die and would not crank over. Waiting a few minutes, it would crank back up like nothing happened. I finally gave in after a starter bolt broke off in the threads. I sold it for what I paid for it to a teenage neighbor. The neighbor was fully aware of the repair history.

I've been in sheer ecstasy with all the Oldsmobiles diesel talk on your channel lately Adam....

I am driving an 1984 Oldsmobile Cutlass Ciera Brougham Holiday with a 4.3L V6 diesel. It has aluminum heads on it, get 38 mpg(Hwy 75mph) has very good pick up for a naturally aspirated diesel. I also have a 1981 Riviera with the 350 5.7L V8 diesel and I had a 1982 Oldsmobile Toronado 5.7L diesel that had 484,000 miles on it when it got rid of it. I never had any head gasket issues, I changed the oil every 3000 miles religiously used only Kendal D3 30, when Amoco was around their Premier Diesel fuel, changed a lot of water pumps, couple radiators, A/C compressors and a few starters and that was it. But I also knew I wasn’t driving a Corvette, I drove it like a diesel, let it warm up a couple minutes on first start up, if I got off the highway after a long drive I’d let it idle a couple minutes before shutting it off. It’s like driving your couch down the street! There was a lot of blame to go around, GM had to know an engine with a 22.5:1 compression ratio and pistons that decked out had to be clamped tightly conversely customers (not all but many) didn’t really read up on their new Diesel engine, they would use dry gas(anhydrous alcohol) when they got water in their fuel, next thing they knew their IP failed, all the gaskets had broken apart from the dry gas. They weren’t putting the correct oil in the engines, they required SF/CC or SF/CD rated oil, and they’d use regular “gas” engine rated oil, crank bearing would go, cams would wear , cylinders were scored, or they would use a weight not recommended in the winter and the engine didn’t get the correct lubrication.

My older friend Stan, who was an engineer back in the late 1970's said "if there is a cheaper way to do GM will find it." This was not a compliment.

My Grandfather was a Ford guy his whole life, but he strayed once when he bought a new 1980 Cutlass 5.7L diesel wagon, complete with the woodgrain exterior. He was keen on the diesel fuel economy, and as a teen I thought it was a pretty nice car. But, he had to have the head gaskets done under warranty, and several other repairs as well. He gave up on the diesel Cutlass after only two years and went back to Ford, buying an LTD Country Squire wagon.

It is a measure of GM’e managerial incompetence that it could have some of the world’s best engineers, and still fail to deliver quality engines for around 20 years!!

Thank you Adam, what memories resurface from my 15 years watching your video, it reminds me of my father's purchase of the brand new 1979 Oldsmobile Delta 88 diesel 5.7L, newly built in Michigan and delivered to Baie-Comeau Qc. Seeing the discussions on the internet, I see that the reliability issues were different for us, a fuel water detector was installed by the dealer, a fuel injection pump bleed done by a Detroit Diesel engine tech, and the preventive maintenance according to the owner's manual was always done. Our Oldsmobile was very reliable for the first 5 years, my parents drove smoothly and were careful with their car. But after a 400 mile drive home on Christmas Day 1984, a few miles from home, a "boom" was heard in the engine, and the engine noise became louder. The next morning at home in -20C (-4F), that was the end of it, a bearing cap mount broke as well as the crankshaft. A new engine was installed at the expense of GM Canada, knowing the reliability of the 5.7L :)

I had to read all the comments posted thus far before making my own.

We had an '81 Buick Regal with the 350 diesel. In the five years we owned it we replaced the transmission 3 times and the engine once. When the heads went on the second engine my folks said goodbye to GM forever and switched to Fords. The Buick was very comfortable and got great mileage on the then cheaper diesel fuel, but it certainly wasn't durable. It also had a mix of both SAE and metric bolts on engine accessories, making it fun to replace belts. About 10 years after trading it in, I saw it one day driving around in the Central Valley of California, pretty far from our home, so it was quite the coincidence. Whoever owned it had bought a crate 350 and converted it to gas.