My 2001 Impala 3.8 just turned over 69K miles. It will be 7 years old
on Dec 2007. I bought the car when it was about a year old with 10K
When the car was four years old and about 40K miles, I drained the
'DeathCool' coolant and replaced, and included a new AC Delco radiator
cap. I burped the car at the thermostat housing, and have had no
problems, so far.
Today I took the radiator cap off, and noticed some sludge on the cap.
I have heard that this is an early warning that the intake manifold
gaskets are about to fail, and the sludge is a result of air in the
coolant, or 'over extended' deathcool.
So, should I change the coolant now (again)? Should I just wait a few
days for the manifold gaskets to fail?
Any advice is appreciated.
Sludge usually means air in the system.
Lots of info on the rad cap and other stuff in the following links,
Hmm... is there a single place that lists all the vehicles that have this
I have a 95 GrandPrix that mixed the oil air and water. First hint I had
of a problem was 'goo' getting in the digital EGR valves and a check
engine that would come and go, usually turning on after the car was
run about 25-30 minutes and I decelerated.
Anyway, it finally croaked. I was lucky it didn't hydrolock, and was
salvagable. Flushed and flushed and flushed after rebuild. Now the
thing runs fine. (Just put a new condenser in the thing, and it even
makes ice cubes!)
But I'm wondering about my 99 Intrigue with 3.8. It's got 155K miles
on it and runs fine (other than no AC anymore, so I guess I'm gonna
have to tackle that eventually). At least for now.
Should I be woried?
Worried? No. All GM 60 degree engines suffer the problems of intake
manifold gaskets. Look for signs of leakage around the gasket seal areas on
the front and rear of the block. If you see stains, get a gasket kit and
The engine in Mike Y's Intrigue is the 90 degree 3800 Series II
engine. The major problem with these engines regarding gaskets is
caused by the EGR passage warping the upper intake manifold, which
permits coolant to leak into the internals of the engine. The repair
involves replacing the upper intake manifold (which is a plastic
casting). GM has redesigned this part more than once to alleviate this
problem, and there are aftermarket replacements available that some
mechanics tell me are superior to even the redesigned GM part.
Mike Y, keep REAL CLOSE track of any coolant usage. If the engine
begins to use coolant and you cannot find any external leaks, it is
time to have the engine looked at. If the warped upper intake issue is
caught early no long-term damage will be done to the engine.
Thanks for the tips.
The Olds actually was a fire car. When fairly new, about a year or so,
it had a major engine fire and was junked. Otherwise the car was fine.
The salvage yard owner routinely picks cars like this, mixes and matches
to make a really nice one, then gives them to his wife to drive for a year
or so. Then another car, then another...
However, she liked this one so much she kept it for almost 5 years, then
finally decided to get another. As a result, I got it at about 120,000
miles in excellent shape.
I'm not exactly sure what all the original damage entailed, but I'm fairly
certain anything plastic was replaced in the engine compartment.
Would it make any difference if I could find out what parts were replaced?
I'll keep an eye on it in any case.
What you think, when ready to drain dexcool, just replace with the new
Prestone 150k miles green coolant. This way avoid all problems associated
with dexcool. On my 2000 buick regal, I am thinking to make a switch.
Since I had to drain my van last week to remove the radiator (to replace the
conditioner evaporator core), I replaced the coolant with Prestone.
Surprisingly it wasnt green. It was a fluorescent yellow, and is claimed
to be compatible with all other antifreezes.
In fact, every brand of antifreeze on the shelves in WalMart and Autozone
seemed to be
of the total compatibility variety. I suspect these are HOAT compositions,
know for sure.
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