Printable View
car has 118,000 miles-when cold it has a knock in valve train,top end. seems to diminish as engine warms. i have heard of pushrod problems with this engine-is this agood place to start? this is my first ls1-got it cheap because of this problem & just looking for logical troubleshooting steps
oil flush?
Is it real loud or just barely audible? From what I've read a lot of LS1's make some valve train noise. Mine has a little noise at startup too, but its not that noticeable.
Changing out the pushrods is definitely a good place to start. Its common to bend pushrods at anything over about 6,000RPM in a stock LS1, they are designed to be weak to prevent floating a valve into a piston in the event of a misshift.
You can get a set of chrome moly pushrods for around $120 to replace the stock ones.
Piston Slap IMO.
Agreed completely Piston slap plagues ls1's cold tick then reduces when warm. Doesn't hurt anything and theres nothing you can do unless going internal.Quote:
Originally Posted by JoshieDoom
The only good tip ive found on this subject is to let the temp warm b4 you beat on it.
X3. The 5.3 in my Z-71 does it. Harmless but annoying:brick:Quote:
Originally Posted by JoshieDoom
x4Quote:
Originally Posted by JoshieDoom
I was also kinda freaked out and all the reading I have done points to piston slap, due to short skirts and metals used if i am not mistaken.
like stated above let her warm up before you tear up the road.
Yep.. piston design and the hyperteutic alloy used are the two biggest culprits from what I gather too.Quote:
Originally Posted by sleeper
piston slap isn't so harmless piston slap at higher rpm's causes agresive wear so you wear the engine out considerably faster than if yo just let it idle and warm up. Not so harmless is it anymore
Quote:
Originally Posted by mroth2008
Hmmmmm..... Well my 186K piston slap 5.3 runs just like the day I bought it over 5 years ago.
And once it heats up the piston expands and fills the bore so no more slap. Mine slaps for about three seconds max.
There is NO hard evidence that PS in these motors is anything more than an annoyance.
There was a class action lawsuit considered against GM for this but no actual proof that motor life was comprimised.