GM 3800 series II intake failure: at what mileage?

[dnastrau]

Greetings:

This may border on being a ridiculous question due to so many variables, but I will ask anyhow. Is there a typical mileage range that the GM 3800 series II intake failure happens? I am asking because my in-laws are looking at used cars and there are a lot of these engines out there.

On a related note, I see a lot of GM 3800 series II equipped cars on Ebay and Craigslist with trashed engines most likely due to this problem. It is a shame that a great engine design was spoiled with this design flaw.

Thanks,

Andrew S.

 

[Camu Mahubah]

Sad thing is so many of them are Buicks and such with such great rides!

 

[Warstud]

Intake Gasket or Intake Manifold?

 

[dnastrau]

Originally Posted By: Warstud
Intake Gasket or Intake Manifold?


I guess mileage for both problems. I would think it would be wise to change both the UIM unit and LIM gasket at the same time and hopefully be done with it.

 

[dnastrau]

Originally Posted By: Camu Mahubah
Sad thing is so many of them are Buicks and such with such great rides!


I couldn't agree more.

 

[tig1]

This happened to my sisters Buick with 135K. She scrapped it out for $500. Besides the engine the car was fine.

 

[Trav]

Anywhere between 80-110k is where i see the most failures.
Course some go earlier or later but they all go in the end.

The key to a permanent repair is the new aluminum LIM gaskets from GM or the top shelf felpro (yes there is a less expensive version that is plastic frame like the ones that let go) and an ATP upper plenum.

Ditch the Dexcool after the repair,before it doesn't help much as the poor gasket design itself is one of the reasons for the failure,the Dexcool just speeds things up a little.

 

[tig1]

Originally Posted By: Trav
Anywhere between 80-110k is where i see the most failures.
Course some go earlier or later but they all go in the end.

The key to a permanent repair is the new aluminum LIM gaskets from GM or the top shelf felpro (yes there is a less expensive version that is plastic frame like the ones that let go) and an ATP upper plenum.

Ditch the Dexcool after the repair,before it doesn't help much as the poor gasket design itself is one of the reasons for the failure,the Dexcool just speeds things up a little.


Has GM ever corrected this problem?

 

[Warstud]

You need the Fel-Pro Problem Solver Gaskets.

 

[crazyoildude]

It does not happen to all of them not even most of them

 

[rclint]

Originally Posted By: crazyoildude
It does not happen to all of them not even most of them


You may be correct, but my mother is 3 for 3, and one ruined engine that could be counted as 4 ? Everyone I have every known of owning one for 125K or more will have to resolve this problem in one way or another.

 

[JimPghPA]

They can go anytime.

 

[mechanicx]

Originally Posted By: tig1
Originally Posted By: Trav
Anywhere between 80-110k is where i see the most failures.
Course some go earlier or later but they all go in the end.

The key to a permanent repair is the new aluminum LIM gaskets from GM or the top shelf felpro (yes there is a less expensive version that is plastic frame like the ones that let go) and an ATP upper plenum.

Ditch the Dexcool after the repair,before it doesn't help much as the poor gasket design itself is one of the reasons for the failure,the Dexcool just speeds things up a little.


Has GM ever corrected this problem?


GM came out with a revised LIM gaskets as Trav mentioned. Also the series III came out around '04 that used an aluminum UIM, which is the best fix.

 

[rclint]

Quote:
GM came out with a revised LIM gaskets as Trav mentioned. Also the series III came out around '04 that used an aluminum UIM, which is the best fix.


Which is how the original 3800, and all the inbreed brothers/sisters got it's huge following, and gave the engine it's reputation !! The original gaskets I assume were metal.. it seems most anything they replace metal with plastic in an engine that is heat cycled, and has to come in contact with chemicals it's a loose loose

I'm not against plastics, etc...

 

[Trav]

Quote:
Has GM ever corrected this problem?


Yes and no. GM did develop a highly revised LIM gasket for this repair,it took them over a decade to get it right but it works great.
The Felpro PermaDryPlus is an excellent gasket also,both work very well,retail price is similar.

The other major issue with these engines is the upper plenum.The EGR chimney burns through the plastic plenum.GM didnt fix this as well as the aftermarket did.

ATP makes a superior replacement #10611 with a metal shield around the chimney and a new chimney of slightly reduced diameter,this cured the burn through issues.The reduction in EGR flow from the reduced diameter is very slight if any and causes no running or CEL issues.

 

[cobra7279]

1998 olds intrigue went at 22,000

 

[Spector]

My 2000 Buick at 90,000 is still going I believe. Car was 4 years old when I got it at 24,000 so no doubt original. Somewhere in my future I guess. Although I seem to have developed an oil seal seepage around the pulleys but really minor at this point

 

[cchase]

Ours was fine when we sold it at 90,000.

 

[Eastexan]

I don't understand the negativity!

Between my son's and the wife & I, we have these cars with the 3.8L and no problems so far:
'98 Grand Prix - 280k miles
'02 Grand Prix - 100k
'00 Park Avenue - 150k
'01 Le Sabre - 160k

All of these run like new. We also know several people that have these with no problems.
I know it does happen with some of these, but I think it's overblown.

 

[Ben Boyle]

Our '02 Grand Prix needed it at 175,000 miles.