New noise in valvetrain... ugggh!
7th Gear
Joined: Oct 2012
Posts: 7
Likes: 2
From: Southern Maryland
I have a 2001 ZO6 that had a very similar (exact) sound. It ended up being the number 5 intake lifter. One of the needle bearings on the roller side of the lifter (bottom) failed and the roller part of the lifter ended up damaged. Picture a circle (roller part) with a piece taken out of it. Based on the head needing to come of to replace the damaged lifter, I ended up adding some minor performance upgrades including ARH Headers with H pipe and low flow cats, Callway Honker CAI , cam, dual valve springs, rocker trunion upgrade, and dual valve springs. I am hoping that your problem is something that you can take care of without removing the head. If I can figure out how to post a pic I will post one of the damaged lifter.
Thread Starter
Pro
Joined: Dec 2010
Posts: 508
Likes: 3
From: Tallahassee, FL
It's sounding similar to Gofast1's experience.
Drove it (gently) to shop, noise was there, 45-52 psi oil pressure all the way. Got a call that when they started it to check it out while warm, only 20psi. Let it sit to get cold, restart, 0 psi. We're betting a lifter is demolished and the shrapnel is in the pump.
So, plan is looking like this. It's all gotta come apart anyway, and since the springs, cam sprocket, timing chain and pushrods are already upgraded, and the cam is most likely toast, replace with a little more bumpy one. Change out lifters to LS7's, replace headbolts with ARP, replace OEM Oil Pump with Melling HV. Tune and Dyno.
Wasn't in the budget but WTH!
Drove it (gently) to shop, noise was there, 45-52 psi oil pressure all the way. Got a call that when they started it to check it out while warm, only 20psi. Let it sit to get cold, restart, 0 psi. We're betting a lifter is demolished and the shrapnel is in the pump.
So, plan is looking like this. It's all gotta come apart anyway, and since the springs, cam sprocket, timing chain and pushrods are already upgraded, and the cam is most likely toast, replace with a little more bumpy one. Change out lifters to LS7's, replace headbolts with ARP, replace OEM Oil Pump with Melling HV. Tune and Dyno.
Wasn't in the budget but WTH!
Thread Starter
Pro
Joined: Dec 2010
Posts: 508
Likes: 3
From: Tallahassee, FL
OK, results are in... and it was ugly. Most of the lifter rollers had galling, most of the cam lobes were heavily damaged. Must have been going on for some time. Car was normally pretty noisy so didn't hear it until the dreaded screeching started.
So, new HV oil pump, LS7 lifters and a little more ooomph in the cam (didn't get the exact specs on it, but the power goes a bit further up in rpms now), I'll fill it in later.
Big thanks to the guys at Horsepower Sales! I'm a happy camper.
Pics and video of the damage and the results.
So, new HV oil pump, LS7 lifters and a little more ooomph in the cam (didn't get the exact specs on it, but the power goes a bit further up in rpms now), I'll fill it in later.
Big thanks to the guys at Horsepower Sales! I'm a happy camper.
Pics and video of the damage and the results.
Last edited by FNFastZ06; Aug 31, 2013 at 09:58 AM.
