Jarad Osterhus

I have a 98 Z28 Camaro. It makes a ticking/ knocking sound on cold start up and goes away after warming up. It also makes the sound when accelerating around 1500 and 2000 rpms. I am going to change out the rocker arms. Should I replace the pushrods and the lifters as well just to be safe?

bww3588

iTrader: (49)

Piston slap probably. Normal.

If your going to change rockers and pushrods, may as well do a cam.

LS1121

iTrader: (17)

If your going to replace the lifters you might as well put a set of 243 or 799 heads on because you will need to remove the heads to change the lifters.

FirstYrLS1Z

iTrader: (4)

I,too,have cold start-up piston slap. Common with the 97-98 corvettes and 98 f-bods.

athornt2

iTrader: (18)

Sounds like piston slap. Common on all LS1 cars.

Jarad Osterhus

If it is piston slap wouldn't my car be smoking or something a lot of the time? My car doesn't have any oil leaks or smoke at all. I was thinking it might be a rocker that might be going bad.

athornt2

iTrader: (18)

No. No smoke. I seriously doubt its a rocker issue. Rocker issues aren't very common on our cars. I'm running stock rockers on my race car... no problem at all. If you had a valvetrain issue I doubt the noise would go away once your car warmed up. Do a search on piston slap.

Camaroo1

Its normal noise from what you describe. Keep effing with it until you make real trouble then you will have plenty of noises to worry about! If it runs ok and has good oil pressure LET IT ALONE and enjoy your car.

9WhiteCamaro9

Like others have said, it's common.