Piston Slap

[ziggy1969]

Has anyone had success with GM repairing the 3.4 L engine due to REALLY excessive Piston Slap.

I have read and do understand what causes piston slap and have also read that apparently GM is OK with it. On my 03 Montana, In the non-winter months I can hear it every cold start and takes up to a minute to go away. In the Winter with a cold start it take many many more minutes, like 5 minutes or more.

Is there a certain amount of piston slap that is deamed to be excessive and can be repaired via warranty ? And how is it measured ? I was hoping to see if anyone has had experience with this before I approach my dealer and get snowed.

tia

[maxwedge]

If not accompanied by oil usage or a noise that does not go away, I have not heard of any action being taken by GM for this condition. The only way to measure the cause is to remove the pistons and check skirt clearance.

[Chucky cheese]

This is normal and nothing to worry about. I worked for GM as a mechanic for ten years and back in the begining we changed pistons and honed cylinder walls. This cured the problem for about 20 to 30 thousand KM's and then returned with piston slap again. I even had done it on my own vehicle and it returned. So as an owner of 2 montanas and 1 venture van ranging from 170000Km's to 330000Kms' they all have piston slap when cold and still run fine with no problems. So in other words I would not touch the engine for this issue and I guess that is why GM does not warranty this any longer. Note I do not work any longer for GM or as a mechanic and am not backing GM, just my personal opinion on this issue. I can only say I have had excellent service from these engines with regular oil changes and the only real problem with them is the leaking intake gasket that occurs around 100000 to 150000 Km's. Good luck.

[spike88]

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Lots of great reading within:

http://www.pistonslap.com/whatisit.htm

Hope this helps as well...

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