3.1 v6 - Intake Manifold Gasket, how long should it last?
Miller Gang
gasket replaced for the second time. First replacement was at 51,000. Has
anyone else had this experience with the 3.1? I am told this is normal for
this engine and I should expect to have to do it again at 165,000.
Considering how well this car runs (when it's not swapping oil and glycol
back and forth), I don't imagine I won't go for a third or fourth...
shiden_kai
"Miller Gang" wrote
> I have 114,000 miles on my '95 Cutlass and have just had the intake
manifold
> gasket replaced for the second time. First replacement was at 51,000.
Has
> anyone else had this experience with the 3.1? I am told this is normal
for
> this engine
You were told correctly. I personally do at least a couple of intake
manifold
gaskets a week at work. Plenty more are done by other techs in our shop.
Sorry, Gm hasn't gotten the intake gasket right on this line of v-6's since
their inception.
Ian
George Jefferson
only if the same guy installed it and he didn't learn to use a torque
wrench in the mean time.
Joe Garcia
Do you see the same problems with the VIN C 3800's too and are there any
symptoms?
Joe
Nick
cannot suggest any specific interval between replacements, but if you do it
now at 114,000 it probably will be needed again sometime before the
vehicle's useful life is over. I don't think it has anything to do with
correct torque or incorrect torque, it is simlply a problem with the design.
Unfortunately, even the newer 3100 engines have this problem.
I don't know what other responses you will get, but I would say that it
would not be unusual to need to replace the intake gaskets on a 3800-C
engine. Considering that engine is now at least 10 years old, anything is
possible. All in all, I think the 3800 is much less likely to need this
repair compared to a 3.1/3100 of the same age.
With the 3800-C I would say that sealing of the oil pan is a bigger problem.
The design is somewhat poor in the way the stamped-in "dimples" on the pan
mating surface are supposed to evenly clamp the gasket. Unfortunately, the
gaskets split easily and the stamping process is not extremely accurate.
-Nick
"Miller Gang" <four...@bellatlantic.net> wrote in message
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brian
wrote:
>:this engine and I should expect to have to do it again at 165,000.
>
>
>only if the same guy installed it and he didn't learn to use a torque
>wrench in the mean time.
We also do alot of them by us and just so you know the torque is low
on the 3.1 manifolds
Brian
shiden_kai
"Joe Garcia" wrote
> Ian,
>
> Do you see the same problems with the VIN C 3800's too and are there any
> symptoms?
I would agree with Nick's assessment of the 3800 in regards to the
intake manifold gasket and oil pan gasket. The 3800 does leak oil
from the front and rear rubber seals, but not at the same frequency
as the 3100/3400 series of v-6 engines. The problem with the
3100 gaskets is simply a shitty design....that's it.
Ian
shiden_kai
" George Jefferson " wrote
> only if the same guy installed it and he didn't learn to use a torque
> wrench in the mean time.
No George....I know that it's fashionable to slag mechanics in
this and other auto tech newsgroups....but the fact is that GM and
other manufacturers make their fair share of shit when building
vehicles. Why do you think there are intake manifold failures
that occur in under 20 thousand kilometers? What....the robots
didn't know what they were doing? Intake manifold gasket
replacements on the 3100/3400 line of engines are a fact of life....
it doesn't matter how well you perform the job....eventually it
will leak again. When the 2.8 v-6 first came out, it had a
different gasket, different torque spec...same problem. Ask
any tech who had worked in a GM dealership for any length
of time.
Ian
George Jefferson
:
:We also do alot of them by us and just so you know the torque is low
:on the 3.1 manifolds
:
:
what does the torque being low have to do with it?
Do you think low means not critical?
George Jefferson
:this and other auto tech newsgroups....but the fact is that GM and
:other manufacturers make their fair share of shit when building
I'll give you that, so what happens is a pro knows how to
build a small block by feel, then along comes one that needs
to be done exactly to spec and they leak. You'd think after
a few came back they would learn though.
Miller Gang
heard and I now have confirmation. I've been using the car for about a week
now since the repair and it is running extremely well -- found a very good
mechanic. I'm starting to believe this car will turn over 200,000!
shiden_kai
" George Jefferson " <wrote
> I'll give you that, so what happens is a pro knows how to
> build a small block by feel, then along comes one that needs
> to be done exactly to spec and they leak. You'd think after
> a few came back they would learn though.
You aren't getting it.....the problem is with the GM design.
There are many mechanical systems that fail no matter
how well you follow the manuals. Even when I used to
repair older small blocks I still torqued intake manifold
bolts. I torque manifold bolts on the 3100/3400 series
engines too...and they will still leak again. The only
point I'm trying to make is that there are many mechanical
items that fail after a tech has repaired it that have nothing
to do with their competence or incompetence.
Ian
Richard Garneau
this job ? No power tool, plain old ratchet etc.
How goods are the service manual ?
Do we have better chance to succeed if we use aftermaket gasket kit ?
Thanks
shiden_kai
"Richard Garneau" wrote
> I would like to know how long it takes for a good"shadetree mechanic" to
do
> this job ? No power tool, plain old ratchet etc.
The flat rate for the job is approx....5-6 hrs, but it can be
done in much less time. But for the amateur with hand
tools, I'd say it would take 6-8 hrs.
> How goods are the service manual ?
> Do we have better chance to succeed if we use aftermaket gasket kit ?
I don't think the aftermarket gaskets will be much better.
The important thing with these gaskets is to realize that
because they have a very low torque on the bolts, it's
essential that you clean the manifold bolts and re-install
a good thread locker on the threads. This keeps the
bolts from backing out even though the torque is only
about 10-11 ft lbs.
Ian
Chuck Browne
I just replaced mine in my 97 Malibu, @ 60500 miles. Noticed a big
coolant puddle in my driveway, looked inside and found orange stuff all
over the right side of the engine. Got the gasket replaced, and so
far its back to normal.
-Chuck
John
like that (knock on wood). It doesn't use oil and it runs fine. So as far as
I'm concerned they should last forever or until something internally breaks
which would necessitate the gaskets to be replaced.
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