I heard it for the first time over a year ago, wasn't sure what it was and it didnt come back for the longest time and when it did I took it into the dealer and they said there's nothing they can do about it. So I left it and last year it was happening again so i brought it in again and the dealer (diff dealer) said the same thing theres nothing we can do about it because it wasn't doing it all the time.

I have read about it and GM is bad for it. Wondering if there's anything I can do to help the situation or provide the dealer with so they will fix/replace pistons or engine if need be.

This isn't my car but the noise that im getting it was it sounds like at the very end of this video
http://smg.photobucket.com/albums/v1...Video-0005.flv

 

I have forged Wiseco pistons that are cam ground and they slap when the engine is cold. They quite down shortly after warm-up.

 

How bad is piston slap exactly?

 

Piston slap can cause premature wear of the piston or cylinder wall. In my case, just don't run the engine hard until it has had a chance to warm up, which is common sense for any engine really.

 

Most newer cars will have some piston noise on a cold start. The way it was explained to me is there is almost no piston skirt on the pistons anymore. On older engines, the skirt was longer and stabilized the piston better. The problem with long skirts is power and efficiency robbing friction. A short piston will not be tight in the cylinder until a little heat is generated, so they rattle a little for the first couple of seconds when you start a cold engine.
I imagine the Wiseco have almost nothing below the wrist pin. Maybe less than stock pistons?
Dennis

 

I would feel some what ok about it, if it happened when the engines cold. It NEVER happens when the engines cold. it only happens after I have been driving the car for a while shut it off to go inside or go to eat or something where I can kill at least an half hour to and hour and than come back start up the car and start driving. It does make the sounds till after i start driving and I always notice it at the next red light or turn.

 

In that case, are you sure you are hearing slap?

 

im pretty sure, but i dont know what a loose timing chain tensioner sounds like. That could be it as well, Anyone?

 

At least you don't have a Neon...
http://youtube.com/watch?v=4ROF4v8g38w

 

any other input?

 

I have piston slap. I mentioned it to the dealer when i had some other warranty work done 2 months ago. They said they couldnt reproduce the noise and that it may be normal. I made them document it in my R.O. so it is in the system. Most GM vehicles have piston slap. Some worse than others but ive only ever read of a very few cases where an engine was replaced due to slap.

 

Change your oil and use a good quality and correct grade oil. if your running the car very very hard, then maybe go to a 10w30 oil.

 

oil gets changed every 5000kms and its always Mobil 1 5w30. I never really run the car hard.