Ive been running my LT1 car for the past 7 years. I just got a ls1 car. Due to my lt1 is more of a race car now. I wanted something I can drive everyday and have fun. I got a knocking sound from the engine it has 100400 miles on it. I pulled all the push rods. None were bent. I put it back together. Removed the belts the noise is still there. At first it sounded like it was under the intake. I got under the car and its louder. I rev it up and thenoise speeds up with the engine. Its holding great oil pressure. Im thinking craked flywheel or rod bearing. What could this be?

 

could it be the legendary piston slap that plague most ls1 cars.

 

Well Ive been working on this car all day. I bought it wrecked. Im fixing it now. It wasnt running when I got it. I just drove it down the road with the ticking. I got on it a little bit and the noise went away. I came home let it sit. Then let my wife drive it. No noise to be found now. It musta been sitting for a while and needed the lifters pumped up.

 

sounds like piston slap to me.

 

keep an ear out...that piston slap will come and go...quite irritatingly. I would suggest a change of oil to royal purple 10w-30 (use it in my bird and never have had the piston slap) I say royal purple because i've used it since I bought the car w/a little over 28,000 miles and not once have I had piston slap. I've got 115,000 on her now.

Some people will say no use this or that....decide whatever I'm just giving u MY results.

 

Ive never heard piston slap that loud. It was loud. But if it was piston slap it was. All I care is its fixed now. And I have nice red painted valve covers LOL.

 

AIR tube leak?

 

www.pistonslap.com alot of examples on that site....have fun