BillS

iTrader: (13)

I just got the call from the dealer service dept ( car is still under warr) and the light tapping noise my wife heard turned up to be one of the displacement on demand lifters had failed at its roller and that in turn wiped the cam lobe. Now the car is waiting for the parts to be shipped in. Turns out that the valve train for the 6.0l Gt is not that common. they would not convert it to a LS3 system due to the fact that GM is paying the bill so all stock.
If GM did not step up and pay it would have been on a trailer down to Slowhawk for an aftermarket cam and removal of the DOD system

cdubbzz

iTrader: (11)

your car is a *****.....my G8 ate 4 lifters + a cam

Slowhawk

iTrader: (12)

Those valvetrains suck badly. Mine collapsed once at 300 miles and then pumped back up. Heads were off at 400 miles throwing that crap in the trash.

DannoWS6

iTrader: (5)

The L76 and L99 suffer from the same valvetrain issues? Is it due from the DOD side of things?

I find it amazing guys chew these things up that quick. Is it always the lifter to go first?

deft

iTrader: (7)

I wouldn't blame DOD just yet. The FWD LS4 guys have DOD with little engine issue. Transmissions are another story.....

BillS

iTrader: (13)

From what I have been told, the DOD uses a special lifter that collapses when the ecm cuts its oil flow. It is big and heavy and can limit high rpm use. What happened to this one is the roller failed and ate the cam

edmanet

Pull that junk out and get a real cam.

GrannySShifting

iTrader: (10)

They do that pretty regularly. Been through a half dozen or so of them doing that

03turbomach1

iTrader: (2)

See this all the time lately. Not just in the g8s. Have had a bunch of newer 6.2l Denali truck and yukons loosing lifters, cams, few have broken valve spring and trashed the engines. Used to never have all these issue with Gm engines and wiring might i add. Really a disappointment.

GrannySShifting

iTrader: (10)

I think there was a change in oils about two years ago, I never saw a lifter wheel worn the way pattern Ive seen a bunch of them since. Starts out as a tick, then a tap and then chews **** up. If you catch it early, they have all looked like the wheels are skipping across the lobe, not a valve bounce necessarily, just skidding.

2QUIK4U

iTrader: (7)

You would be wise to take it and have an aftermarket cam put in anyway. That is what I did. Best decision I ever made on my G8. If you have factory crap put back in it is likely to fail again and more than likely it will bea fter the warranty is up and will damage more than just the cam and lifters.

KnightmareCS

iTrader: (15)

Would the aftermarket cam make your gas mileage worse or would you just get a milder cam that would lower the performance?

2QUIK4U

iTrader: (7)

I had a pretty aggressive cam in my G8 and only lost about 2mpg. The fun factor more than made up for the loss in mileage.

nikon1999

iTrader: (22)

My new 6.2l sierra denali motor on start-up sounds like a piece of junk in the cold, far worse than "piston noise" in my t/a and z06.. It's getting worse and starting to concern me, a whopping 10k miles on the truck... Truck has no AFM or DOD

03turbomach1

iTrader: (2)

Gm say this is normal if it go's away once it warms up. What a joke. They say its is caused by carbon on the pistons and because of the 6.2 not having larger piston skirts, Heres the bulletin # 01-06-01-028B

03turbomach1

iTrader: (2)

Oooo yea, it also says this in the bulletin in a high lighted area.....Important: At this time, attempts to repair this condition by replacing the engine assembly or pistons are not recommended.

Slowhawk

iTrader: (12)

Since it's your wifes car I would just let GM fix it under warrenty.