1997 Eldorado ETC Overheating problems, Please HELP!

[Eslag]

I hope I am posting in the right spot. I have a 1997 Eldorado ETC, 108K miles. It had a crack in the radiator upper right side. I replaced the radiator and tstat, but, its still overheating after about 15 miles. I have flushed the block and new radiator, cooling fans work, pass over not plugged. I have run it with and with out tstat. I am at wits end. All I can come up with is the heater core (which shows on signs of leakage)

It has also developed a good miss, I think I need to replace a couple coils, no biggie, unless it is related to this.

Any help or advise is GREATLY appreciated.

[Cadillac Jim]

The first thing I would want to do is to run the OBD codes from the A/C buttons. Press <Off> and <Pass Warmer> (up on the Pass rocker) simultaneously for a few seconds until all the dash lights come on like you just turned on the key, then release them both. The OBD codes will be displayed one at a time o the driver information center (DIC). Write them down and post them here.

The second thing to do is to have the coolant checked for combustion products. This check for head gasket leakage. There are two things you can do to check for head gasket leakage: with a cold engine, take off the radiator cap, and watch for bubbles in the coolant, and smell the overflow tank. If there is an exhaust smell and bubbles, you have head leakage. The other thing is right after you start up in the morning, let it run for just a few seconds, shut it off, and go around to the back and see if the exhaust smells like coolant. If it does, you have head leakage.

Your mechanic may prefer to do a cooling system pressure test. Although leaking hoses and such are detected that way too, if the cooling system is tight it will help diagnose head leakage.

[Eslag]

Current Codes are: P0300, c1783, c1785

Still need to do the checks for Head leakage.

Thank you so much!

[barczy01]

Check your purge line and make sure its not plugged. When the car is cool open the radiator cap, if it smells like gas in the recovery tank, you probably need head gaskets. Does the car start up smooth in the am after driving the previous day?

[99EldoETC]

Here is a video of Tim Carroll (Carroll Custom Cadillac) performing a coolant test, that Cadillac Jim mentioned above) on a 2000 STS with "extremely blown head gaskets."

[Eslag]

Guys,

Thank you SO much for the information. By doing the above mentioned tests, it head gasket. Definite exhaust smell in purge tank and small bubbles. I was hoping it was not. I was repairing to sell it, now I will rethink what to do.

[Cadillac Jim]

There are ways to fix it that will add more value than the repair will cost, all of them involving getting the engine repaired locally. Kelley blue book for a generic 1997 ETC is about $3600. You can ask what recycling yards will pay and work with those numbers.