Tech

A friend was driving when the normal LS7 sewing machine sound turned into a loud tick and then the car began running very rough and his dash lit up like a Christmas tree. He didn't see any oil or smoke but it was dark. His first inclination was either a valve let go or a valve spring broke. I jumped in my truck and drove over there, found him sitting in a pile of his own excrement with tears running down his face. I popped the hood, shined a flashlight in the engine bay and his nightmare was realized. Something definitely broke.

EDIT: Car has about 25k miles and stock heads. 2011 MY

njk4o5

so what your saying is, it could be 1 of 230978348957389145 things?

Suns_PSD

Denial is not just a river in Egypt dude.

Lawdogg

Sorry to hear about your friend's trouble. Let us know what the failure turns out to be. My guess is that this is another nail in the LS7 head denier's coffin. Stock heads are like a grenade with the pin already pulled.

DustyShamrock

Cool story. I had a car break down too!

moose.b3

In before the usual suspects come in and say "Very few LS7's have head and valve problems".

CrystalRedZ07

Everything else also stock in addition to the heads? Tune? Sorry to hear this!

njk4o5

so many of these threads on here. engine dies. valve drop assumed. OP never returns to let us know...most likely due to original assumption being wrong.

takes 15 mins to pull valve covers and see

Tech

Everything was stock as far as he knew. It did put down higher than expected numbers on a Mustang dyno though. 462 rwhp if I recall correctly.

BRISLS1

A 2011 with low miles, and an unmodified car, but doing lots of time on the dyno? red flag already

Probably still under some kind of warrantee or service agreement.
Why is the owner "sitting in his own excrement"?
Why is he not towing the car to a dealer, and why are we hearing this second-hand and not from the owner himself, as he is likely to continue to own this car and read CorvetteForum for even longer now?

These posts are all so half-baked, it's impossible to draw any conclusions.

MTPZ06

^ Maybe he's not a forum member...but then that's impossible as LS7 failures only happen on this forum.

Tech

Who said anything about lots of time on a dyno? He made exactly 3 pulls.

Because he @#$# his pants thinking he needs a new motor.

Because there is no need to tow the car to a dealer.

The owner is on the forum. He just doesn't post much. Not everyone runs to CorvetteForum when their car breaks down.

MTPZ06

A few threads on here about 2011's dynoing a bit higher than previous years, and most attributed it to the first year GM added an X-pipe, and the last year for the 2-cat setup (meaning 12's & 13's have an X-pipe but with 4 cats).

Tech

I asked this particular dyno owner, on the day that he made those pulls, how his numbers compare to DynoJet numbers. He said he's had multiple cars go from a DJ to his MD1100-SE, and his was always 11-12% low. If you add that back into my friends 462 rwhp, it's a factory freak at well over 500 rwhp.

MTPZ06

If that rule of thumb applies, then yes...that would be an odd result.

lamboworld

I have a 2011 and my baseline on a dynojet was 470whp and 445wtq.

Tech

This thread was a bit of an experiment. Everything I said was 100% true, except the excrement and crying part. He was very concerned that it was indeed a broken valve. Loud ticking, running rough.. those are definitely things could happen if you broke a valve or valve spring. As njk4o5 said, there are many other explanations of what could have broken. People jump to conclusions here far too quickly. Nobody asked what I saw when I popped the hood. Seems like a good question to ask someone who said they _saw_ something broken. A spark plug wire was broken. Took me longer to drive home to get him a spare than it did to fix it.

MTPZ06

That's about what I've seen reported typically on stock 2011's. Part of the reason I chose to add an X-pipe to my '09.

Landru

At first glance thought it was your Z, Tech.

Just curious.
No idea re relationship, but had you never had a conversation with your pal concerning the possibilities?
IF I encountered one/more C6 Z06s while out cruising, stopped & talked?
You can bet your bottom dollar, even w/ complete strangers I'd have mentioned the 'issue'. Curious what they've to say as owners, if anything.

Sorry for your friend, keep us abreast of post mortem.

Tech

My friend is aware of the issue. We've talked about it a few times and he says he'll address it sometime. He was definitely worried that this fiasco was what most of the people in this thread thought. Fortunately, spare LS spark plug wires are plentiful in many of our garages.