I just got my car about a month ago and it has had slight piston slap since I got it but it seems like it comes and goes, not really dependent on engine temp. It didnt worry me since ive heard that some piston slap is normal on some LS1s. But i did my first oil change today and it seems like the piston slap is a bit louder/more noticeable than it was before. I used 5w30 as recommended and it's definitely filled to the proper level and has good oil pressure, about 40-60psi depending on engine speed. Any ideas why it would seem worse after changing the oil? just a coincidence?

 

99% of the motors people say have "piston slap" just have the traiditional gm valvetrain noise. my ls1 has it. my dads 6liter has it. when I adjusted pushrod/lifter preload on my last cam install you can hear it getting louder/quieter.

 

Maybe a diff brand/thickness then before. If the oil was clean(no metal etc..) when you drained it and it has good oil pressure I wouldn't be to worried, just get in it and stab the gas and have a good day. i'll admit it can be a scary sound when you're not used to it.

I'm on my second LS1, my first car didnt have piston slap. the car I have now does and it bothered the **** out of me so to cure the "problem" I threw on some headers/true duals & Heads/big cam and now the piston slap sound is all gone.