97 Deville Overheating

[adallak]

Never let a shop to flush you transmission. Just drop the pan, clean it up, replace the filter and fill it up with fresh ATF. I would change the motor oil first.

[BodybyFisher]

There is a method to exchange the transmission fluid yourself. You disconnect the upper transmission cooler line, attach a fitting to the radiator, attach a hose to the fitting, direct the hose into a large bucket, start and IDLE the engine, keeping the car in park, let the transmission pump, pump out the tranny fluid into the bucket, as soon as it begins to spit fluid, turn the engine off, reattach the cooler line, and refill. You will get much more fluid out than if you were to just drop the pan

[Cadillac Jim]

If you do decide to flush the transmission, be sure and use Dexron VI. There are still people out there who sell Dexron III but GM pulled the license and specs years ago and there hasn't been any *real* Dexron III since about 2006. See http://en.wikipedia.org/wiki/Dexron for a paragraph on that (scroll to end of article).

Dexron VI has been the GM-recommended transmission fluid for all GM transmissions using Dexron or Type A/Suffix A transmission fluid since 2005 and is backward compatible with Dexron III and Dexron II. If you flush, you get 100% Dexron VI and you get the full benefits of Dexron VI over Dexron III, including very consistent viscosity from a cold transmission to running temperatures, which improves shifting in Cadillacs because the PCM remembers shifting characteristics and adjusts for perfect shifts. And, you more than double the remaining life of the transmission.

[igotaseed]

O k put the belt, pulley, and tensioner on. I drove it...it still ran hot. The car has this hesitating feeling that happens at like 3 second intervals. It seems like its trying hard but hesitating. Today Im getting the oil changed for the 1st time since I had had it. I am also getting the transmission drained (15 qts are expensive!!!!) I got a mechanic to help me out with these things, Hopefully he'll be able to find out why its still running hot....reaching around 225.

[adallak]

After fixing water pump, do you have flow through that purge line?

[winterset]

If you are still overheating, I would not change the oil & transmission fluid just yet.

We are all trying to help, and sticking to one issue at a time is how we'll move forward.

check that you have enough coolant, and that the air is burping out thru the purge line.

does your coolant overflow tank smell like exhaust?

You may have to get your coolant tested for exhaust gases (checking for blown head gaskets) - rent the tester & buy the testfluid at Autozone.

[BodybyFisher]

225 is not hot, when does it hit 225, what are the circumstances?

[Cadillac Jim]

At this point, I wold check the fans (both on HIGH with the A/C on, even with a cold engine), the coolant level and mix for 50-50 antifreeze, and the overflow hose.