This might be a noob question but im new to the LS scene and was just wondering can you drive a car that has piston slap/rod knock? and would you feel a decrease in power with one or both happening. And what signs besides hearing it would be there?

My buddy wanted me to ask this for him thanks!

 

Piston slap and rod knock are two very different things.

Rod knock is very bad, and is an indication that the engine is on the way out.

Piston slap is nothing to worry about at all. Many LS1s have done this since day one, and they still run just as long and make just as much power as a non-slapping LS1.

 

oh ok thanks for the help brother

 

i think PSTNSLAP would be a good lsx plate XD

 

That's too many letters

PSTSLAP works

Or...PSNSLAP...but that sounds odd.

 

Exactly, I know mines will slap slightly until it gets to nearly full operating temperature. My friends with LS1 T/A's will do it when cold, my Dad's LS2 Corvette and 5.3 Suburban will make a decent amount of valvetrain noise when cold as well. So, I'd say it's a pretty common thing on LS motors.

 

it's not too many letters in NC

 

Wow, I had no idea piston slap was normal on LSs. I'm glad I read through this thread

 

Yea the pistons are just so short in these engines. It should go away once the engine is warmed up but some higher mileage ones you may still hear it warm. Trailblazer SS and Vettes do it too. I don't hear it much in the trucks though, maybe the piston design is different. PSTNSLP would be the license plate to have