I enjoy your videos and have learned some very useful applications from them. I have a 1989 XJS v12 and had to go through my cooling system about three years ago. I replaced all the hoses and had the original radiator serviced by a rad shop. I did the back flushing with water and had to replace the water pump. I added some inline filters and buttoned it all up. I didn't replace the thermostats. After a few test runs and sorting a few things out the cooling system works very well. This car is my daily and I have been driving it in 90-100 degree days in traffic and the needle is staying under the N. On days under 90 degrees the needle is way under the N. My car has over 91,000 miles on it and from this experience I have found that the the Jaguar v12 cooling system is sufficient for keeping the engine cool, at least in my car.

@lebojay

Жыл бұрын

Great to know! I’m picking up my refreshed rad from the shop tomorrow!!

had a 1972 jag XKE 2+2 V12 in the SF Bay area back in the 70's, dang car ate batteries so bad AAA canceled me for calling them so many times. The car didn't have enough air circulation in it for warm weather driving like where I was. Drove it down to Irvine on the 5 FWY and had to NOT use the A/C and had to stop every few miles to let it cool off. Parked it in the garage when we got to the house in Irvine, took the entire water cooling system apart and re-routed pipes, replaced pipes, new thermo, roded and cored radiator, hooked up the fans to run all the time. That did the trick, drove it to a import place and sold it in 5 minutes! Now drive a 2013 XJ and no issues at all.....

Be aware that factory jaguar maintenance schedule for coolant leaks was to use bars leak. As a result original radiators may be partially blocked so a new radiator or re-core maybe needed. On my 1989 XJS there is an overflow tank behind the driver side fender between the front tire and the door. You can acess it by removing a panel in the wheel house. This tank is feed from the overflow hose in the side auxillary tank in the engine bay. This hose will connect to the overflow tank via a metal nipple (behind the fender). On my car this nipple was totally blocked which effectively removed the expansion tank from the system. Anyway you'll want to check to insure your expansion tank is sorted.

I live in west central Florida and own two V-12 XJS’. One is a 1988 and the other is a 1990. The 1988 has a Lucas ignition and the 1990 has a Marelli system if that makes a difference. The 1990 has no overheating issues, whereas the 1988 experiences the same overheating symptoms as ‘Ol Tex. I can drive mine and it exhibits a normal warm up cycle and maintains a normal gauge reading for a few miles. Eventually the needle will begin a slow creep until it is in the 210 degree range. I won’t let it get any hotter than that for fear of engine damage. I too have done everything you have shown through your episode #3 with the same results as you have experienced. I have also removed the pre-catalyst to reduce exhaust back pressure, replaced the water pump, replaced the radiator with a 25% larger capacity, replaced the radiator fan with a high capacity electric one, replaced the thermostats several times with three different opening temps, overhauled the distributor because of sticking advance weights, replaced the vacuum advance unit and flushed the cooling system three different times. A Jag forum suggested flushing with a 5% white vinegar. I drained the system completely and replaced it with nothing but the vinegar. I drove it 100 miles like that before I drained it. That was a difficult procedure since I could only drive it about 20 miles without overheating. I was shocked at what came out of the cooling system once it was drained. Like the stuff you got in your drain pan that you didn’t know what is was. If you poured the coolant through a coffee filter and allowed it to dry it would be a light brown powdery substance. I believe it is a substance called Bars Leak. Jaguar recommended adding it to the coolant at major service intervals. I got a massive amount of it from my system so I repeated the vinegar flush procedure once more. I got a very small amount on the second attempt. To make sure that I got all the vinegar flushed from the system, I flushed the the system a third time with a commercial product made specifically for aluminum engines and cylinder heads. I have done this, and even more, and the warm up and overheating condition is unchanged. It remains exactly the same. I look forward to any solution you come up with that would solve both our dilemmas.

My 89' V12 XJS started overheating under very similar circumstances with me eventually trying new thermostats, coolant mixtures, even some fancy liquid to lower the boiling point of the coolant. Eventually, the motor started getting hotter and hotter until it overflowed into the overflow tank located behind the front left wheel. With each subsequent drive, fluid just kept going into the overflow tank and then the ground as it overheated during very hot days here in Northern California. At some point, blue smoke appeared out one side of the rear exhaust. When I took the heads off (no easy task), I found that both gaskets had large holes the size of quarters that appeared to have been there a long time. Not sure how bars leak would have helped. I also did not realized the V12 motor is "wet" around the cylinders, unlike many motors with a solid block of steel/aluminum that would warp or crack. I have read on many Jaguar forums that replacing the head gaskets should be done every so often. Bummer it takes so much work and is not an easy job.

I would guess you are probably right about the thermostats. Look forward to finding out 👍

I really think you should change the thermostats and maybe add a Spal electrical cooling fan on the radiator. Just my two cents. By the way, I really enjoy the videos.

bob...this reminds me sooo much of nigel when i first acquired him. as to hills and overheating..i found out real quick. i live in the shenandoah area of the blue ridge mountains. flat happens on rt 81 and a few other places. that's it. 🙂

Great videos, have a similar issue, so just working my way through, doesn’t help that the temp gauge isn’t working so that’s my first priority

Good progress! Did the company have anything to say about doing the flush twice, back to back with a drive between. Anyway, after flushing the rad and confirming working thermostats, I'm betting Ol Tex will be working fine.

There are other unique things to the north American market. One is federal pollution control systems. The '75+ Pre-HE, for example, makes less horsepower at lower Rpm, and less torque at HIGHER rpm than the "rest of the world" model. There is an excellent chance these engine run hotter to begin with and are more intolerant of wear or poor tuning. Also, these engine were designed to run on leaded gasoline. The US effectively banned lead in gasoline in 1975, England did not until about 1989. England has also just in the last few years begun using E10 "gasoline". These sources of leaner running/friction/heat may be enough to make the V12 overheat outside of nearly optimal conditions.

Good of you to chemically treat and flush the radiator, but the chemical may need more time to clean out the build up of crud from the past several decades. A second treatment may return some more cooling capacity. You were wise to see the A/C adding some temperature rise as an indicator that you are just on the edge of the cooling system’s capability. Back flushing the radiator may return some benefit as it may loosen up more crud, but I think more chemical cleaner exposure time is the key to breaking more cooling tubes open in the radiator. (It may be very difficult for the chemical to penetrate down the most clogged cooling tubes in the radiator as the majority of the flow will want to go down the tubes that are already cleared out)

@thecampchaoschronicles9567

Жыл бұрын

I don't look for the radiator to be the problem. It was a fresh reconditioned unit two years ago.

@richardp6178

Жыл бұрын

@@thecampchaoschronicles9567 But crap from the engine block could have blocked the new radiator.

@noelnicholls1894

Жыл бұрын

I’d think you have loosened a lot of that crap. Just not all. Do that chemical flush again and you’ll clear out more of the water channels in the block.

It will be interesting to see how much more junk comes out of the radiator after this run. Shame there is not a simpler flushing method.

Would a second treatment offer an improvement?

Why do these Jaguars always have cooling issue and corrosion issues in the cooling? What's is the stock coolant? How about switching to "Asian Vehicle" Red coolant. Seems to do better in Bi-metal apps. I think the system is capable of keeping the engine cool it just seems to have longevity issues. What was that stuff in the flush? Rust?

@thecampchaoschronicles9567

Жыл бұрын

I'm convinced the cooling issues are due to lack of proper maintenance/repair and perhaps faulty replacement thermostats. I'll be checking the latter in the next video. I use the recommended coolant. I'm researching the stuff in the flush. I've emailed Irontite about it.

@richardp6178

Жыл бұрын

Do not use any other coolant than green coolant in any Jaguar! The cooling issues are down to lack of maintenance. I've been working on these cars for 30+ years, trust me on this one.

@paulb1034

Жыл бұрын

Best corrosion inhibitor for these engines was and still is the Bluecol ethylene glycol anti freeze.

@lebojay

Жыл бұрын

I think it’s because careless owners use tap water. I figure it takes 20 years for tap water to ruin a cooling system, so most people never give it a second thought. But then guys like us come along and buy their 20-year-old cars, and that’s where the fun starts. 😠