hey guys..ive got a very bad case of piston slap in my 02. 42K on the odo. it seems to be most prominent at 1K to 2K rpm (the beginning of each gear especially 1rst and 2nd) . i run 5.75qts of mobil 1 5W30. i also notice that my gas goes pretty damn quick compared to my old LT1. question is..is there anything i can do to lesson the sound of the slap? thicker oil? anything? also do you think i could be getting bad gas milege bc of bad combustion due to the lack of seal betwen piston and bore? also do you think my PCM is picking up knock, thus retarding my timing bc of this piston slap. my LT1 would pick up crazy knock even with a LT4 KM. all comments and help is appreciated. thankyou

 

little help

 

well, you could buy a mustang. that's what most f-body guys are doing now since gm is so stupid. but that's about it!

 

ok thanks

 

 

That is a good way to spend $20K+ and run in the 14's..why would anyone with a LS1 want to do that???

 

anyone want to help this guy?

 

I would never buy a stang. I was just making a dumb comment to bring up the point that he can't do anything about it besides rebuild the motor, and use aftermarket pistons! It's the way the pistons are designed that makes them slap.

 

is it a problem though? gas milege? combusiton? power loss? or just a noise annoyance is my question

 

does it burn oil, and does it go away when you warm up?

 

burns oil and does not go away when warmed. just gets quieter..seems to only be heard at 1K to 2K in each gear. car runs so strong though

 

My old 02 WS6 had piston slap, but it was still under warranty. The dealer put new pistons in and the problem went away.......sold car to gf and she has put about 10k on it with no issues.

 

If it still under warranty I would take it in and demand they fix it. If it is not wait and see what happens or put in new pistons, rings, and get it honed.

 

since its not normal piston slap and is always there,,, is it more of an annoyance noise? or performance robbing/ engine ruining thing?

 

GM considers piston slap to be "normal" in our engines. They will not fix it unless you are losing a certain amount of oil. In my case I was losing almost a quart a month. When they took it apart they found that the rings on one of the pistons were lined up so that oil was coming into the intake.

I actually complained and kept on bringing it back for "noises" so much that they gave me an 04 ls6 block because that didn't make the ls1 anymore . Plus the fact that it went through an extended warranty company which didn't give me the GM run around.

 

I would change the brand of oil. My '02 had a bit of slap when I bought it. I think that why the previous owner gave me that deal. I put in Royal Purple oil instead of Mobil and it went away. Now I have Mobil in it again, but I cant hear anything now because of the heavy cam.

 

well im running 5.75qts of mobil 1 5W30. think the same amount of german Castrol Syntec 0W30 M0501 would help?

 

The new gold GC 0W30 is not the same as the green. I just switched to Amsoil 5w40 and it quited my piston slap a little. You might want to try that or the Mobile 1 5W40 T&SUV. The 5W30 Mobile 1 you are using is too thin. My slap goes away when warm and I do not use any oil.