New to the forum but hoping I could get some advice..... Bought a used Z06 about 8 months ago after selling my 05 Z51. Thank goodness I bought a 07 with a warranty still on it.

Took my 07 Z06 Vette in about 4 months ago for a tick under warranty. Around 1900 to 2100 RPM it had a very distinct tap/tick. Not normal valve sound. You could hear it through the RPM but it was very distinct around that RPM range.

Turned out to be a blown rocker arm. They replaced all the rockers with updated parts #'s (likely due to the dreaded rocker arm flaw). They also had to re-seat a valve that was damaged. I later found out they didn't do the best most proactive measures to eliminate additional damage. They didn't recover all the needle bearings, test the oil filter or oil for shavings/etc... When I asked the mechanic he said many were broken so they couldn't tell how many there was.

After it was supposedly fixed I picked it up and still had the same tick. Really couldn't believe they gave it back to me and didn't notice or maybe they hoped I would just go away. Took it back in and they said this was a different noise and most likely it was "injector noise" and to keep driving it and see if it got worse. Noise got worse so I took it back to the dealer a week later. They had it for a week or two and could not figure out what was causing it. They finally decided to replace the whole bottom end because they thought the sound changed when the clutch pushed in (which it didn't). After taking the whole bottom end apart they didn't find any issues and replaced with all new pistons, rods, etc....

Picked it up after the bottom end was replaced and it still had the same tick. At this point I am dumbfounded that they would return it to me a 3rd time with the same issue like they had fixed it. When I took it back they called in the regional service manager and he called an engineer and they said "oh that is normal noise, LS7's are traditionally noisy." I couldn't believe they would work on my car multiple times for a noticeable tick then try to say it was normal. After arguing with them a few more times after it continued to get worse they finally took it back in again. The mechanic then said "wow that is a lot worse" and found a large amount of play on several of the valves due to wore valve guides on the drive side. When they compressed the spring they could move several of them far more than what the tolerance was supposed to be. They then decided to replace both heads.

Picked it up again and sound was gone...or so I thought. A month later it started to come back. Almost the exact same noise. Took it back in again and they are now sending a regional engineer in to look at it. At this point I don't feel I should settle for anything but a new engine.

All I can figure that would be causing this is a oil delivery issue. At this point they have broke into it multiple times and there has been so much metal in the oil I do not see how it could not have caused premature wear through out the engine.

Any ideas on what could cause this and any suggestions on how to get them to replace the whole engine? I bought it used so Lemon Law is out but the federal Magnuson Moss Act may apply some.

Total time in the shop over 2 months
1st time blown rocker arm
2nd time still had tick (replaced entire bottom end but found no issue)
3rd time found valve guides were wore and put new heads on
4th time......to be determined waiting on the regional engineer.

Car Info:
07 under warranty
Stock except for air intake and mild to wild switch

z06guy07, I give you alot of credit. I don't know how you had the patients to deal with all of that. It sounds like they pretty much gave you most of a new motor, aside from the crap they put you through. It probably would be cheaper for them just to replace your motor w/ a new one. I wish you luck and hope everything works out for you.

Well I must say you have been thru alot. I think the only thing left to replace are the cam, lifters and cam bearings. What is the oil presssure hot, at idle? A couple of bad cam bearing can bleed off enough oil to starve the lifters. Is the noise worse at start-up? or when warmed-up? Who would think a hand built engine would have so many issues? I'm wondering if this engine was badly abused by the previous owner or the used car dealer had it's way with her.

This is probably too late to help you, but I strongly believe in Oil Analysis. I personally use Blackstone Labs in Ft. Wayne, IN; www.blackstone-labs.com although most major cities have one. Of note is that some oils, especially GM oils use Titanium as an additive so don't panic if Ti shows up in your ZO6. Get a good baseline and go from there.


K.