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Cadillac Repair/1992 Cadillac Deville


QUESTION: Hi i am not sure how much you will know on this subject but. I have a 1992 Cadillac Deville 4.9L V8. Well I spoke too soon. Today I was filling my radiator up with coolant to test my system out. I replaced the water pump the radiator the hoses and the water outlet. I thought I did the inlet and thermostat but I did not. I ran a flush through the system. I dumped all the contents filled it up with new fluid it was running perfect for a good 2 weeks. I dumped it filled it up with new today and all of a sudden it started pumping up brown fluid up that smelled like oil. It was a terrible smell almost like when you disconnect the oil lines from that radiator is what it smelled like. I have gotten a lot of bad radiators from that company where I bought it from. Most of them had cracks in it and I had to destroy 5 of them. The other problem was it was not sucking the fluid down it was flowing over and also going into the back up resivore. Any suggestions why it drained out green and now it is brown. Their is no water in the oil or transmission fluid I checked their. Also from what I can see their is no blown head gasket.

ANSWER: Hello,

Unfortunately, I know far too much about the issues of the Cadillac cooling system and associated problems with the aluminum engines, however this one you really have me on. I do not understand what exactly I am looking at in your photo. I see your hand and phone, but do not understand the field of view I am looking from.

If coolant mixes with oil, the end result is the fluid is white and milky. If mixed with red transmission fluid, the end result is a pink color. If the oil cooler broke in the radiator or the trans cooler, those are the two different colors I would expect to find. Not brown, and I know what you are referring to as the smell, but I can't think of anything in the cooling system that would create that similar to a real strong nasty hydraulic smell like that of burned fluid in a power steering pump or steering rack.

I have seen nasty brown fluid that got stuck in between air pockets in a flush, but that is generally rust from the coolant breaking down from an overheating situation.

I do not understand either as to how you drove it for two weeks and all of a sudden the resivior is bubbling over.

Why did you change these parts in the first place? Was the engine overheating?

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QUESTION: The heater core was clogged was clogged the radiator had a crack in it and was leaking in the fin part the water pump just lp lain out went at 135000 miles while driving. The old serpentine belt slipped off. So I just put a new one on when I replaced everything ang keeped the old one as a spare. I changed the hoses just because I had everything apart and also the water inlet had holes in it and was rusted I brazzed the old one but I also bought a new one for like 75.00 dollars but that is why I changed all this. I actually drained all fluid yesterday it was green when it came out. I did this because I wanted to make sure I got all of the flush out of the system. I closed the radiator drain plug and filled it up. I started the car it sucked the fluid down a little then all of a sudden it started to gush over it was brown like what was in the the bucket and smelled like either the oil cooler lines or the transmission lines. Maybe one of the broke on the inside. I have had 5 of these radiators replaced so far so it would not surprise me something like that didn't happen. What is your opinion? Thanks.


As I said, I usually go by the white or pink color, but I suppose it is possible that there is a temendous amount of oil gushing into the radiator, but to my knowledge there is no check valve and I would think the crankcase would have milky colored oil.

I have seen just about every failure one can think of with a Cadillac cooling system, but I have not run across what you are. Percentage says though if you have had that many problems with where you are getting the radiators, you are probably right in which there is a crack in the coolimng tank in the radiator.

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QUESTION: I just drained the transmission fluid Friday. When it started draining green coolant came out of the transmission pan first then after awhile a milky brown oil drained out. So some how the two mixed which leads me to believe it was the radiator. Now my next question is is 200 dollars too much for a transmission flush after I already took the filter out replaced the lip ring seal and drained all the fluid out of the transmission. Also should I even worry about getting a flush done the car has about 138000 miles. I was planning on just replacing the radiator filling the transmission up with new fluid and replacing the filter and then in another 3000 miles changing it again. What do you think would be in my best interest. Thanks.

I don't care about the miles. in this case it sounds like the transmission fluid was compromised and I would not think twice about the $200.00 for a trans flush. Your converter and valve body are filled with coolant which will cause imminent failure.

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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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