1988 Cadillac Brougham Overheating

[talon92]

Hello Everyone,

I am really hoping someone has a suggestions on this. I recently purchased a 88 Brougham, it has a 5.0 in it and only 65,000 miles on it. The guy I bought it from said it had a blown head gasket. Well what we found was the valley pan gasket was rotted out. There is no smoke coming out of the tailpipe and there is nothing in the oil. Everyone I have talked to said it cannot be a head gasket then.

We have flushed the radiator out completely and put 3 thermostates in. We filled the reservoir just to the add line. By the time I go 50 miles, it is ready to overflow. When the engine cools, its empty. It got hot last night on me but the Coolant Temp light did not come on. This AM, the reservoir was empty and I opened up the radiator cap and I could not see the water in the radiator. I put 1 gallon of water in the radiator and it almost came up to the top. I put nothing in the reservoir. I drove 50 miles with it, the Coolant Temp light went on and off during this time. When I shut the car off, I opened the hood and the reservoir was full and about to overflow and the radiator cap was making a high pitched sound. I will go out when it cools down and the reservoir will be empty.

Can someone please help me??? There are a few of us pulling our hair out wondering what is going on. Any info would be greatly appreciated.

Thanks!!

[MagicRat]

You have just described a blown head gasket!

Blown head gaskets can produce a variety of symptoms. Depending on where they go, you may or may not contaminate the coolant or oil. In your case, the compression from the engine is leaking into the water jacket and over pressurizing the cooloing system. This is pushing the coolant out, and mimics an overheating problem.
You can remove the plugs and pressurize each cylinder with compressed air(when the valves are closed) and watch for bubbles coming up to the rad cap, to determine which head it is.
When you pull off the head, send it out to a macine shop to be checked for straightness and cracks. A cracked casting (head, or (rarely) engine block) can produce this problem, too.

[fergy623]

Magicrat is correct as I have just gone through this same problem as well but I am kinda fubar-ed at the moment as I have photos of where all or some of the vacum hoses go but not all and I removed the defective air pump at the same time and now I have a mess of hoses and no directions as to how to replace them. It would be appreciated if there is a link as to where all these hoses go. and good luck with yours. as mine runs and no leaks just poor performance as I guessed where the vacumn lines would go!!!

Originally Posted by talon92

Hello Everyone,

I am really hoping someone has a suggestions on this. I recently purchased a 88 Brougham, it has a 5.0 in it and only 65,000 miles on it. The guy I bought it from said it had a blown head gasket. Well what we found was the valley pan gasket was rotted out. There is no smoke coming out of the tailpipe and there is nothing in the oil. Everyone I have talked to said it cannot be a head gasket then.

We have flushed the radiator out completely and put 3 thermostates in. We filled the reservoir just to the add line. By the time I go 50 miles, it is ready to overflow. When the engine cools, its empty. It got hot last night on me but the Coolant Temp light did not come on. This AM, the reservoir was empty and I opened up the radiator cap and I could not see the water in the radiator. I put 1 gallon of water in the radiator and it almost came up to the top. I put nothing in the reservoir. I drove 50 miles with it, the Coolant Temp light went on and off during this time. When I shut the car off, I opened the hood and the reservoir was full and about to overflow and the radiator cap was making a high pitched sound. I will go out when it cools down and the reservoir will be empty.

Can someone please help me??? There are a few of us pulling our hair out wondering what is going on. Any info would be greatly appreciated.

Thanks!!

[Antiburn]

Chilitons or a Haynes manual has the complete diagram. There should also be a small diagram on the metal plate directly above your radiator.