My 2001 recently started making noise from the engine so I took it back to the dealer. They cautiously tore into the engine troubleshooting the whole way to find the source of the noise. It sounded like a sticky hydraulic lifter. I had even changed the oil, disconnected the accessory belts to listen, etc.

It ended up being the roller on the intake valve No.1 lifter. They showed the parts to me and the surface of the roller had degraded and worn away, ruining the camshaft of course. The service manager thought that the roller may not have been case hardened or that the lifter guide was misaligned. You could see that the plastic guide was out of kilter on the No. 1 lifter. This sounds like a quality issue to me. They hesitated to cover it under warranty saying that I had revved it too much. ... Baloney !! :bs I am going to make sure that they return the old parts to GM engineering.

There was a thread about valve noise last summer. Has anybody else heard of problems such as this with the LS6?


[Modified by tjfees, 12:52 PM 7/9/2002]

 

Well, that definitely sounds like a warranty/quality control issue. If the lifter bore is in fact out of alignment you do not want that engine. I would contact GM directly as it sounds like the dealer is a dick. The more I hear these types of stories the more I am convinced that all warranty/dealer discussions/phone call should be tape recorded and the person informed of this. I think just the knowledge that you are taping will have a magical effect on the dealers demeanor. How can they refuse? They have nothing to hide if they are being fair and accurate. If it ever does go to court you are way WAY ahead of the game.

Good luck and keep us posted.

 

Could you describe the noise in more detail? For example, how loud was it? Where is that roller located on the engine (front/rear/drivers/passenger-side)? Did the noise change with temperature?

The reason I ask is my 2002 Z06 is noisey when cold (sounds like lifters or injectors). The noise appears to go away once the engine is very warm (perhaps 1/2 hour of operation). Private mechanic said it is was loud relative to other Z06's they've worked on. Dealer states normal. I'd like to either not worry about it or get it fixed...

SportsCars

 

Searching this site found posts from 2001 where valve-train-like noise was considered normal...

SportsCars

 

My 02' Z06 has no valve train noise.
It has 467 miles on it and no noise.
There IS some noise when the car is at idle and out of gear but most have reported THIS noise as normal.

Good luck with your Vette.

 

Sitting in the car, idle, out of gear, not very much noise (perhaps able to hear one noisey-lifter-like noise (or perhaps injector)). With hood open, listening in the engine bay, there is noise when cold, but virtually none when hot. Sure sounds like the "normal" condition from other posts. If this is not normal, then perhaps it's a common build variance defect. As long as it does not lead to any failures, I'm not going to worry about it. I had the noise checked at the dealer at ~1000 miles.

SportsCars

 

I hear the fuel injectors firing - that CAN sound like lifters to some folks -

best of luck with your repairs

best regards -

mqqn

 

My 2001 made the same "cold noises" as yours, especially in the winter. This noise is more noticeable when the engine is cold at startup. This is normal from carbon build up I believe. A can of 3000 mile valve cleaner in the fuel helps that. Fuel injectors make a slight click - click - click sound that you can hear at idle. Normal.

The lifter noise I had developed after I got used to the "normal" sounds. It was more like a stuck hydraulic lifter on an older engine and more noticeable at idle. Did not change with temperature. I did not hear it so much at speed, and I really took it easy when I suspected a more serious problem. If you had this problem you would notice it and any reputable mechanic/dealer would too.

I don't know about the lifter bore, but the plastic insert was out of alignment. That is getting replaced. The roller surface was shot and the cam lobe had a worn groove all the way around it. No Wonder !! It's on the driver's side, first lifter - most forward.

They are fixing it under warranty, but the dealer tried to claim that I voided the warranty with the mods I did. I don't think that they would change the engine. Live and learn. :nonod:


[Modified by tjfees, 7:55 AM 7/10/2002]

 

Hmmm, I wonder if this is the same problem my car has. I've listened to several other Z06's, and mine definitely has a louder valve ticking/clacking sound. Its odd in that it comes and goes from time to time. It's most noticeable from idle to 2,000 RPM, and after that can't hear it anymore. Sometimes its quite loud, sounding like an old taxi motor with 400k, othertimes its completely quiet.

What I have noticed is it ALWAYS is loudest after I restart the car after its fully warmed up and had been resting for about 10 minutes or so. Doesn't make any sense to me. During cold starts, its not particularly loud, but during hot starts its very loud.

I had the dealer listen to it, but they came back and said they couldn't hear anything abnormal. I suggested they get their hearing checked. :rolleyes:

I'm thinking it must be a lifter problem, but what exactly I don't know. I would think if it was a roller problem I would hear the noise steadily all the time, not intermittent like mine. Also, the car runs fine - I would think a major lifter problem would cause the motor to run poorly???

Any ideas?? My thoughts at this point is keep driving it until the engine blows apart under warranty, then let GM deal with their problem with a new engine. I've already given notice that something isn't right with that noise, and they chose to ignore me. If something happens down the road, I'll tell 'em "I told ya so!"

 

What a joke! I must have missed the "revving the engine warning" in the owners video. Maybe it came after the instructions on how to drive the car like a race car. :rolleyes:

- Charley

 

You must have used a magic spell to bypass the rev limiter. Hello!

 

tjfees,

I would be VERY concerned with how much of the ground up metal from the lifter and the cam lobe made it's way through the lower end of the engine before it got trapped by the oil filter.
Particularly at risk would have been the crankshaft journals, main bearings and rod bearings.

A failure such as you have experienced calls for AT MINIMUM a COMPLETE engine teardown and rebuild.
Even better, GM SHOULD be swapping out your engine with a NEW one.

It's not your fault the darn thing failed. Why should YOU be saddled with an engine that has suffered a catatrosphic failure?
The dealer is just trying to patch up your engine and send you on your way.
Replacing just the camshaft,lifter and maybe rocker arm for the defective cylinder is without discussion or opinions, a PATCH JOB.

Get somebody at GM involved, the tech rep for your area or whatever and RAISE HE!! about the "shaft job" (pun intended) you are getting from your dealer.

If YOU let them slip it to you on this deal it just makes it easier fro them to "shaft" the rest of us........
Somebody has to fight the battles.

Good luck and God Speed to you.

 

tjfees,

Another thought.
Here's one for you to run by the dealer.
If the damage was caused by "over-reving", why aren't ALL the lifters bad.

Ask them if they can PROVE the engine was "over-revved".
Ask them how they can even THINK an engine was "over-revved" by examing one failed part. What have they got? Some "CRYSTAL BALL" or TARROT CARDS or OUJA BOARD to consult with?
Their taking advantage you. But you don't have to let them because there are a lot of people here that know a LOT about engines and will be glad to point a few things out for you that you might not otherwise think about.

IF those guys are good enough to base their diagnosis on the failure of a single cam lobe or lifter, they should be good enough to lay hands on your car and HEAL it just by saying a few Hocus Pocus,Mumbo Jumbo words and sprinkling a little "magic dust" on it.

Man, it's the order of chaos. The WHOLE world has gone crazy.
There's so many BU!! poopieERS and so very few people that can REALLY do anything. Or maybe nobody WANTS to do anything.

But I digress and will end THAT here.

Again, good luck with your Vette and don't forget it's YOUR car and you don't have to accept any repair you are not comfortable with.
Tell them you're VERY concerned that the integrity of the engine HAS been COMPROMISED due to the failure of the lifter/cam lobe.
Tell them you realize it's not their fault and by the same token, it's not YOUR fault.
You KNOW their service technicians can patch it up and get it back running and it will be ok for awile. BUT since the engine has essentially injested a lot of metal you're VERY conecrned about the long term reliability of the engine and the car in general.

IF you still have warranty, you REALLY need to get a NEW ENGINE.
Yep NEW ENGINE >.<

 

WB6HRO,

That "magic spell" CAN be invoked by grabbing SECOND gear when you're really trying to catch FOURTH.

Another good way to call the magic is trying to grab FOURTH from SIXTH and finding SECOND..... this is REALLY exciting if your running 50 or 60.

Poor ol rev limiter won't help a bit.
Everybody knows by now the valve train is the weakest link on the LS-1 and LS-6 engines.
But that by NO means proves ALL failures of the valve train are caused by "over-revving".

 

Someone, somewhere must know the cause of this noise. Lifter pump-up/leakdown sounds like a good candidate, and/or incorrect rocker (etc.) adjustment (don't know what's adjustable on the LS6). If they *all* don't make the noise, then I'd like to know what parts to replace/adjust to make it go away. It doesn't matter if it's "within tolerance", if they all don't do it, I'd like to make mine like one of the quiet ones.

What's the best way to get a shop manual for the Z06?

If the sound is truly a normal operating characteristic of the vehicle, then there's nothing to worry about (it's not even very annoying from an NVH point of view). :cheers:

SportsCars



[Modified by SportsCars, 4:42 PM 7/12/2002]