Any GM Service Tech's out there?

[DaveN]

I have a 2001 Chevrolet Impala with the 3. 8, and have had the intake recall done. Basically they have a design flaw in the intake where they run EGR gas through plastic, it melts/deteriorates, and then dumps coolant either outside or inside your engine. So to fix it they put some new nuts on the intake and dump some stop leak (yes the ground up walnut shells) into the radiator, give you a smack on the a$$ and see you later. I can see the nuts - but the stop leak really rubbed me the wrong way. I get home and start checking things out, check to see if the radiator is full (gut feeling) and see the floaties in there and about lost it.



So I call the service guys chewing a$$ about what kind of bleepity bleep uses bars leaks, and they told me that's part of the recall. So I apologize, and ask them if GM has a new manifold design available, because I'm thinking of premptively replacing it. He said yes, but GM is not allowing anyone to order the new manifold until they've exhausted their inventory of the old crappy ones. So again I control my anger, politely thank the guy who obviously is having this conversation four times a day and can't do anything about it and crack a beer.



Then, I hear through the rumor mill that the 100,000 mile dexcool they put in there is prone to gelling, which leads to overheating, etc.



I guess what I'm looking for is the straight story on the intake manifolds, and on dexcool. Are the new manifolds available, and are they any good? Is dexcool junk, can I use the regular green antifreeze and just change it more? I plan on driving the car until the doors fall off - and the engine's a pretty important part of that plan.



sure wish they had a cummins retrofit for the impala's...



Thanks -



Dave

 

[MMeier]

Not a GM tech, but I've known about the gelling situation with Dexcool for some time now. Have changed several cars over to Green stuff (Prestone) and no adverse effects on any of them. Also will be changing the mighty Cummins over to Prestone this fall and getting rid of that HOAT stuff that 's in there from the factory.

 

[EBottema]

My cousin is an ASE cert mechanic and lately he has taken me under the wing and have learned about the GM cooling problems.



anyways, dexcool is the worst crap known to man. It gels, causes corrosion, gm says it lasts 150k miles and that is a load of BS.

The intake heater fitting on most GM engines (newer ones) are made of pot metal. They slowly leak, one day they give and you end up overheating and blowing a headgasket, GM sells a new intake fitting that is solid steel, great huh?



I would demand that they fix your car again, once it gets out of your warranty... flush that dexcool crap out and put in some good toyota red antifreeze. the best stuff around!



Erik

 

[MFalkinham]

I own a GM van with DexCool, and have been investigating this problem for awhile, including talking with some GM service techs. What I've learned is that DexCool is OK for shorter periods of time, but it can't last the 5-years, 150k miles that it was originally supposed to. As long as you change it every 2-3 years or 50k miles, it won't cause corrosion or gel up. Of course, this cancels out most of the "advantages" of using the DexCool in the first place.



The other problem is that DexCool is very sensitive to being mixed with air inside of the cooling system. This is how most people get into trouble with it, by letting the DexCool level inside their overflow bottle get low. Once the level drops down into the radiator, and the DexCool mixes with air in that sealed environment, it starts to crystalize and cause all kinds of problems.



Bottom line with DexCool..... keep it full, and change it regularly. If you do switch to the green stuff, make sure you flush out ALL of the DexCool first.



- Mike