Hirohawa

I have 41K miles - original owner - all stock. Had ticking noise needed lifters replaced under GMPP. Intakes and cam ok and in spec.

R&D

It would be interesting to see how many miles people have on their C6Z in general. On the surface, this poll is showing 85% of the problems happen before 50K miles... But, I also tend to wonder what % of people that have C6Z's have over 50K on their cars. A similar poll asking how many miles on your C6Z might bring more light to the relevance to this poll.

LawrenceFromTorrance

I have the heads replaced for bad values twice in less than 50K. Went to AHP heads so we'll see. Should count as two votes but I can only vote once

bjmsam

Glad your cam was not damaged by the failed lifters. Did you vote? I don't see your username in the results.

When establishing this thread, I considered but ultimately decided against including a set of "mileage without failure" categories because 1) a poll is not well suited for dynamic data, and 2) automotive forums tend to attract a disproportionate number of owners who experience problems with (or modify) their vehicles. Perhaps a snapshot could be mined from CarFax (or the data sources that feed it)?

Sorry, as indicated in the first post and reiterated in post 8, this poll includes engines actually lost to a dropped valve but not valves replaced because of stem to guide clearances measuring beyond service limits, which is captured in a different thread.

Hirohawa

Should I vote for just lifters? I thought this was for engine failures.

bjmsam

Please vote if your situation was similar to post 13 and GMPP replaced the lifters to prevent impending engine failure.

A similar case could be made for valve-to-guide clearances measuring beyond service limits, but as that already is covered in a different thread, this thread covers valves that actually failed.

Thanks!

nchristle

2007 corvette z06, dropped my exhaust valve at 39k miles.

449er

How about a poll of all LS7 owners that have NOT had an major engine failure

baxsom

56k miles. Multiple guides were at the upper limit when i did the heads

Z.06

13,000 miles valve guides out of spec. Heads replaced by GM.
28,600 miles valve guides on replacement GM heads out of stock. Replaced with AHP Stage IV with Moldstar 90 valve guides, PSI valve springs, Ferrea exhaust valves.
28.600 miles multiple cam lobes failed on Comp Cam. Valve lifter completely failed. Replaced with AHP116 cam, GM lifters, GM oil pump, oil lines, cleaned everything else.

Keppler

I bought a pristine '09 with 15k miles yesterday. I pulled the heads today. I need to decide between Katech and AHP.

Spacewalker

After viewing many different mileage heads in person, these are my beliefs:
1) All exhaust valve guides were out of spec within the first 5k miles.
2) Some TI intake valves slowly wear on the stem.
3) How long exhaust valves last with the beating they take from worn guides is a crap-shoot. 15k, 25k, 35k, 90k, 150k infinity - not all stock hollow stem valves have uniform wall thickness.
4) if you get lucky on number 3 you could still be unlucky on number 2
5) if you get lucky on 2 and 3, you could still spin a bearing.
6) Some people have all the luck and a car built on Wednesday.

Prime Target

I just traded in my stock 2006 Z with 18,800 trouble free miles on it. I never had the heads checked but I never heard any ticking from the motor. I got to the point where if i kept it I was going to have the heads checked/upgraded due to the known exhaust valve issues on the LS7. If the motor lives at 5k + RPM’s, then your chance for valve failure goes up at a lower mileage point. The cars that are highway driven and live at 1800 RPM go pretty deep mileage wise before you hear valve failures in them. Either way, the valve issue is certainly real and a costly one if the valve breaks. I guess I was lucky with mine.

Ed Cackowski

HI Rocket Riders !!!!
I have a 2013 LS7 bone stock with 32000 Miles . I recently sent an Oil sample to Blackstone and their reply was " engine seems to be wearing well" along with a long list of metals etc they tested for . They compared my numbers to an average of results on similar motors they have done and everything seems in line.

Has anyone that suffered an engine failure received a Blackstone report that indicated high level of metals pointing to potential problems ? . If so what metals and at what level ?

Thanks to the vast knowledge represented on this Forum.

Kurt Semon

I just used Blackstone this past May but didn’t get a negative report back; my sample was sent in at 38k miles. The oil only had about 400 miles on it. After the test, I drove My 2008 Z06 across country in June and averaged 30 MPG with a loaded trunk and the A/C on. I just mailed another sample in yesterday. I’ll let you know what comes back.

Kurt Semon

I have a 2008 Z06 that just passed 40k miles last week (and I’m the second owner). Haven’t heard any issues with it yet, I probably should have it looked at. Note: I drove across country (Central Texas to Kansas City) last year and then from KC to Southern Oklahoma last month (military life). I had no issues and even managed 30 MPG. Also sent an oil sample to Blackstone but nothing negative came back in the report.

Chad97z

Not only that, how many miles do they have and HAVE NOT had ANY Internal engine problems.
The reason I ask is because I see a 2009 Z06 with 68,000 miles, and wondering if it will fail or has it passed the danger zone of 30-40k miles as the Poll suggests.
https://www.corvettewarehouse.com/20...-75220/6945602

dmuellenberg

The problem with a poll like that is that most people don't know if they have an internal engine problem or not. Just because they haven't dropped a valve doesn't mean they don't have a problem with worn guides. I had 100k on my stock engine with no noticeable problems but decided to have my guides checked. Almost every guide was out of spec, one so bad it wouldn't even register on the gauge. There is no 'safe zone', just because you reach a certain mileage doesn't mean you aren't going to have an issue. I've never understood this theory, it's like saying I've got 50k on my tires and haven't have a flat so I don't have to worry about it. The guides in the LS7 are a wear item, and the more miles you put on your engine the more likely your guides will show excessive wear.

Chad97z

True. But I already know that all GM motors expire by 100k miles. Beyond that, you're going to have too many problems with the entire car , not just the engine.
so ya, all those parts are wearing out by 100k, doesn't matter if it is an LS7 or the atypical chevy small block.
But what I want to know is will it last to 100k without modifying the damn thing. And this poll only identifies how many people on this website that has had problems. It doesn't include those who had no problems. So I can't get a Percentage of failure.

so IMO, the poll is nearly worthless, except for showing most have failed 30-40k miles

Apocolipse

lol what is so special about 100k miles? That isn’t very much now a days…the rest of the world has figured out how to last much longer than 100k so why hasn’t GM?