'99 Grand Prix Overheating problems

[Jose Jimenez]

Last night I was driving my 99 V6 GT Grand Prix when the "check engine soon light" come on. Then, I saw that the temp was upto 235 (3/4 of the temp gauge). At that time I exit the freeway, and stop at a gas station just outside the freeway. When, I got there the car was surging, very low power. I then turn-off the car and opened the hood. We checked the water level and was almost empty, which is the first time that it happens. We put water to the radiator and started the car again. Then temperture gauge when all the way down, but there was white smoke coming off the mufflers, and started to shake. Then, I turned back off and tried to started it again, but it didn't start. We jump-started it, and the motor made a very bad noise and I stop. Need some help and what to do now?

[JJUBECK]

White smoke is never a good thing, it usually indicates a seal leak or something wrong with your major engine parts, such as a piston ring or a blown head gasket has been known to do the same. My suggestion is to do a compression test on it. Now I could be wrong and in this case I hope I am. Good luck!!

[kilroypr]

There is a way to refill the radiator on a hot car. If the car was almost empty you should have waited for a while until it cools off or add water with the engine running. If you add cool water to a really hot engine that is off you might end up with a blown head gasket or other major component.
Once my cas was to damn hot it had a rought idle, not starting at all. I waited 15 mins then started the engine and added water.
If you add cool water to a hot engine that is hot you might cause dissaster. Something will break because of the sudden temp changes.

[pawn]

When my belt came off, my water temp got all the way as far as it would go might have been over 260+ yeah serious. I never had white smoke come out my pipes or anything. She barely made it up the driveway. I let it cool for an hour and came back to start it and it started right up just fine, no problems. Today it runs like it did new....anyway, Did your engine turn over when you tried to start it? Sometimes the piston rings can actually weld itself to the cylender walls, which is a big problem...

[dragon459]

I had the same problem with my car. I am going to assume that you have the 3.8 V-6. What happened with mine was the intake manifold had started leaking coolant into the engine. It ended up hydro-locking the engine. I found out that this is a common problem with this engine. It sucks but at least it is fixable. Good luck!!

[hamot007]

Same problem here as well...just dropped $1200 on it. Worked ok for a week...now a lifter sounds to be not fully pumped up. Not sure if its a coincidence or not. Took it back and they said it might go away, otherwise they may try running a little ether and then a better oil(synthetic) to see if it clears up.

[JTikkanen]

Originally Posted by dragon459

I had the same problem with my car. I am going to assume that you have the 3.8 V-6. What happened with mine was the intake manifold had started leaking coolant into the engine. It ended up hydro-locking the engine. I found out that this is a common problem with this engine. It sucks but at least it is fixable. Good luck!!

I had same issue with 3.8 V6 with coolant leaking into engine. I replaced the upper plenum and now have a bent piston as a result of that upper plennum crack. Heard it is a very common problem (and expensive) and I pursueing a complaint with Pontiac.

[hamot007]

Ended up replacing all of the lifters...another grand down the drain. Safe to say that it wasn't a good month for me. But the car probably runs better now than it ever has.

[kilroypr]

Sorry to read that, never pour cool water on a non idling really hot engine. Major problems will happen