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Lifters? Valve Train? Piston Slap?

5K views 4 replies 3 participants last post by  bw03z 
#1 ·
I'll start this by saying my 01 Z is the first LS powered car i've owned so i'm still getting used to the normal sounds. I've noticed a slight tick that comes at cold starts or even if the car has been sitting for a few hours. It seems to go away when oil temp comes up but sometimes its still slightly audible when at low rpms when starting from a stop.

I've built a few small block ford motors so I like to think I somewhat know what i'm doing lol. Anyway my guesses are either a) lifters taking a minute to pump up or b) piston slap. I've stethoscoped the whole top end and everything sounds great other than the injectors being loud. It does kind of seem like it is coming from the bottom end but again could be lifters (definitely not heavy enough to be rod knock).

Let me know what y'all think. I can upload a video later if that might help.

Side note: the car only has 34k miles
 
#2 ·
Piston slap was common on the early LS engines. It was so bad that there was a web site dedicated to the problem. A few have had the engines swapped out under warranty but, more often than not, nothing was done. Valve train noise is common in all LS engines to a certain degree. I had an 02 that had it bad. Problem turned out to be sloppy lifter bore tolerances which let the lifter bleed down thus increasing valve clearance.

Unfortunately, there is no easy cure except for running a loud exhaust or sound system.
 
#3 ·
I've been dealing with the same issue for awhile now. Alot of ppl will claim piston slap but I know that the "tap" I'm dealing with on a cold start is not piston slap... the piston slap is more of a hollow knocking sound. I believe mine to be related to a lifter, I'm just not sure in what way. Could be a sticking lifter, could be a lifter bleeding down and pumping up, maybe a damaged lifter thats failing, or possibly a lifter that isn't positioned correctly due to a damaged lifter tray. I have checked enough to know it's nothing in the top end also. Now the question is do I have the heads pulled and replace everything or not worry about it. I assume you are in the same situation.. do you have a video or audio clip? I can send you a video of mine if you want to compare.
 
#4 ·
To be honest, save yourself a lot of grief and worry and just drive it. It might be noisy but it won't let you down.

You have a high performance, aluminum blocked engine, that's what they do.

If it proves to be too much for you to deal with, sell it and buy another.
 
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