Cadillac Repair/Radiator


QUESTION: Hi I have a 1992 Cadillac Deville.   I have put in 3 radiators and all 3 have gone bad on this car. They last 200 miles and that's it. I bought 2 off eBay the one busted and the transmission cooler broke and leaked in my transmission the other just leaked out the seams. I had 4 of them that leaked out of the seams. After the one that the transmission cooler broke I went to autozone and bought a oem one. This one lasted 200 miles and is now leaking and my radiator fluid is milky brown and it is thick. How can these keep going bad could their be an underlying problem that I am missing. Thanks.

ANSWER: Hello,

I have a guess, but I want to know something first. How many times has this engine been overheated? Was it driven over 30 seconds with the hot light on or the temp gauge over 225? I do not think you will like my answer, but I believe the problem is not in the radiators, but much more severe.

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QUESTION: The engine has never been overheated if the engine light comes on it is shut down immediately. On this car their is no temperature gauge. You can only tell if it is overheating if the light comes on. I dumped what was in their out and it actually was not that is was an orange rust color with sediments in it from the flush. So I flushed it again and the system was clear. I put radiator fluid in it and I have not seen it leaking so I am not sure where it was coming from. I also replaced the radiator cap with a pressure cap that has the red lift on it so it can let the pressure out before you open it. I thought maybe a head gasket was gone or a head was cracked. That's what I was afraid of. Thanks.

ANSWER: Hello,

You did not say how long you owned the car before having the radiator issues. I am thinking a head gasket or worse yet a cracked block.
Di you check the oil? Is it milky colored?
These aluminum engines were great for economy and performance, but if over heated just a little, turns into pig in a poke. The worse thing is that you will not find a good used engine in a salvage yard because as a general rule, that is why they are in the junk yard. The engines were junk from overheating issues.

Have a cooling system pressure tester put on the radiator. Start the engine and if you see fluctuation in pressure, it is head gasket, head or engine block time, at which point you are looking at a minimum of $1,500.00 and the car is simply not worth taking the chance on repairing.

Don't get me wrong, but I have owned over 20 Caddys, 99% with aluminum engines. I was fortunate enough to not have issues with the 4.1, 4.5, 4.9. However, I do not believe yours has that pig Northstar of which from the factory had an automatic oil change in it, swallowing quarts of oil. I believe they were introduced in 1993.

From your description, it sounds like pressure is building in the radiators and now with that thick brown colored radiator fluid, you are introducing pressure caused by one of the piston pumping pressure into the cooling system y one of the three ways discussed.
In 15 years on this site, this is the second time I have heard of such an issue, o it is not common.
I do not believe that the radiators breaking at the seams were defective. I believe you have an internal engine issue causing this event. Sure, its possible to have a bad trans cooler tank, but replacing more than one radiator is telling you the problem is not in the radiator.
These cars ran engine oil coolers as well, but even if that ttank was broken internally, you would not have broke the other radiators at the seams.

Good luck

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QUESTION: We have owned it 20 years in September it will be 21 years. This is the first real issue we have had with it. The car has been good to us besides the cruise control doesn't work and I have been through everything on that. I think it is the lever or I am not sure if their is a switch in the column. Someone broke into it and broke the steering column and ignition switch and ever since then it hasn't worked. But like I said this car has been good. I will most likely get it pressure tested to be on the safe side. The good thing is I have a friend that owns a bunch of junk yards that can probably find it and install it for me. Thanks.


Tips when looking for an engine at your buddie's yard:

No rust in the radiator or overflow jar. Its been over heated.

Run a pressure test on that radiator.

Look for trails of green running past the heads on the block from under the car.
If it runs, if warmed up, watch for white smoke from the exhaust. Head gasket.
Obviously, check the fluids for milky color.
Let me know what you find.

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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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