My 2001 Malibu V6 knocks for about the first 10 minutes when cold. I think
it is called Piston Slap.
Can anyone please tell me more about the problems this creates and what can
be done to minimize any damage.
I learned from somebody in a NG about piston slap just after our Malibu
went out of warranty. Apparently it is something that occurs on 2001 and
newer 3.1L V6 engines due to GM using skirted pistons.
I heard rumor that GM was extending the warranty to 6yr/100,000mi. Is this
I would like to learn more, especially how to make this engine last as long
as possible, or if GM is doing anything about this problem.
Thank you for any insight you can provide!
Are you saying that this problem just now started after 4 years? While it
may indeed be piston slap, that is an issue which usually comes on much
sooner than this. I had a single occurance of what you may be describing on
an older truck I owned - turned out it was a sticky lifter and an oil change
with a good quality filter did the trick. Anytime I'm approached by friends
with similar problems, that is the first thing I tell them to do and more
often than not it fixes the issue. A while back, someone posted on one of
the newsgroups I read that cold engine knock was particularly an issue when
using cheap Fram oil filters which is what I had on my truck when it
happened to me, but I have no way of verifying that (I use Purolator filters
Search for "piston slap" on this and other GM/Chevy newsgroups and you
should have enough reading to keep you busy for a long while.
Cheers - Jonathan
The noise has been there for some time, but I just didn't think it was a
I've had many oil changes since I first noticed it. It just seems to be
noticeable now that I'm aware of it, or maybe it's actually getting worse.
I never really quantified it early on, but it seems like it used to go away
2 to 3 minutes (a year ago). Now it lasts more like 8 to 10 minutes with
without freezing tempatures. I have 51,000 miles on it now.
A while back, someone posted on one of
I will look at what kind of filter I'm using, but I don't believe it's a
I get all the oil changes from the same place.
Thanks Jonathan, I'll read some more so I can determine whether I'm
being foolish hoping to get 200,000 mi out of this car.
Usually, one or two of the pistons will exhibit badly scuffed
skirts...it rarely does any damage to the cylinder walls. There
is nothing you can do other then replace the pistons or just
live with it.
You should "easily" be able to have this repaired under
warranty. We've done 98 and 99 Malibu's under "goodwill".
GM knows about this problem, and I've yet to see an
engine that needed pistons in our shop "not" go goodwill.
The big thing is that it needs to be verified by a shop foreman.
Usually, the procedure is to leave it with them overnight, let
them do a cold start, if the noise lasts for more then about
2-3 minutes...it's a done deal. At least that's how we do
Any dealership that is smart will be quite happy to do this
job. It pays almost 14 hrs under warranty and can be done
quite easily in under 7 hrs. It's always a big scramble in our
shop to see who gets to do one of these jobs. Nothing but
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