3800 series II any favorites?

[302Xplorer]

Would there be enough coolant that would leak to where you would notice it missing or is very little coolant enough to do bearing damage?

What kind of damage is done to the bearings and how does it show up in driving?

 

[lght1]

Hi

The problem with the Series II 3800 is that the EGR chimney is ported up through the LIM to the intake airstream via the UIM throttle body neck.

As these engines get older, especially pre-99 model years, the UIM can either warp or actually degrade in the EGR chimney port to the point that coolant is actually introduced into the engine.

The LIM gaskets can fail as well, but usually at near 100k miles. These failures, while distressing, is much less frequent than the 606 engines.

The fix for anyone that has a 3800 SII with 60k or over, is to replace the LIM gaskets with the new aluminum GM one ( part # 89017816 ) and use a Dorman UIM kit (part # 615-180 ). These newer kits have the reduced EGR chimney for the early '99s and older Series IIs. After mid year '99, the LIM EGR was reduced in diameter making this part unneccesary.

Use thread loc on all LIM fasteners, torque them in 3 steps to the prescribed value using the recommended sequence. The same goes for the UIM.

I used the L26 aluminum UIM on mine last year, and since it was before the new aluminum GM LIM gaskets arrived, I used the updated plastic Felpro.

So far..so good. But if a UOA looks like a leak, the new LIM gaskets go in.

FWIW, I have a OEM UIM with 70k on it that has already started to degrade and a Dorman with 100k on it that is pristine.

 

[T-Keith]

The EGR problem is caused by an air bubble in the intake IMO. When coolant through is flowing it is fine. DEXCOOL destroys the plastic lower gaskets. IMO if the coolant is changed properly(no EGR until the air is out) and regularly you will not see any problems. GM sealant tabs do their job well.

Don't let all the intake stuff worry you, I've yet to see a 3800 fail at less then 200,000. These engines will take a beating and still get 30mpg.

-T

 

[302Xplorer]

quote:

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Originally posted by T-Keith:
DEXCOOL destroys the plastic lower gaskets.
-T

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I switched the DEX out long ago. So maybe my gasket is still intact.

**waits for blackstone report**

 

[Mach5]

A friend of mine has a '94 GrandAm with the 3.3L engine (low-deck version of the Buick V6). The car has 237,000 miles on it and runs like a top...burns no measurable amount of oil. The car has had a steady diet of Valvoline dino every 3k miles its whole life.

This last weekend he finally had to replace the intake manifold gaskets. This marked the first time the engine has ever been apart.

 

[lght1]

Hi

quote:

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The EGR problem is caused by an air bubble in the intake IMO.

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I think its more likely that the almost pressed fit and less than robust construction of the UIM is the culprit.

That used Dorman was on an older, larger EGR chimney and it was a very smug fit.

After '99, the EGR chimney was reduced, and the failure rate was lessened..but still serious.

After '99, instead of expecting failure around 65k or so, it seems the 2000-2003s will do 100k and over.

I wonder if there was any differences in the 2005s that still used the SII ?

 

[Big John]

I ran Syntec 5w20 in the wifes car,checked the uoa in the appropriate section..

 

[Spector]

Using the Amosil 10W30 at 7500 OCI WITH GOOD UOA 3800 SC version. Engine is easy on oil in terms of not beating it up. mine uses about a quart in 7500 so in an effort to reduce that consumption I am going to use a 50-50 mix of Amsoil 5W30 series 3000 and 10w40 for a slightly higher viscosity and see what happen. Mix is ready to go in next week. Will see.