Wndotintman

If your car fails the wiggle test, what do they replace? The whole head or just castings? Thanks.

GMuffley

Just the valve guides that are worn---with the same OEM guides.

Mark2009

I've heard of all the following:

1. Some dealers have replaced just the castings (come with the guides) plus whatever the shop that does the rebuild/reassembly work considers 'worn' (probably the exhaust valves if the stems are galled). In this case I have heard of owners paying out of pocket for new exhaust valves if the shop considers the old ones okay.

2. Some dealers replace the entire heads.

3. Some dealers send the heads out to a local shop for new guides (bronze, I'd imagine) and again, whatever parts the shop considers 'worn'.

#2 is probably the only one I'd be comfortable with.
#1 or #3 would be okay if I knew/trusted the shop and knew they would be using good parts.

Oskee

My 2008 Z06 (original owner ) just this last May with less than 10K miles failed the wiggle test, the dealer in my area(Able Chevy in Rio Vista) replaced both heads with new guides and valves 2 weeks before my warranty expired. Plus they gave me a rental car while my Z06 was at their dealership for the repairs.

pkincy

Oskee,

I am having trouble understanding your sentence. New guides and valves or new head castings with new guides in the new castings and new valves assembled in the new castings with the old springs, rockers, etc?

Hopefully the new castings have better guide machining.

Being close to Abel you can check them in 10-15,000 miles and than hopefully relax.

wjnjr

In my case, new heads and valves were sent to a local machine shop where the heads were blueprinted and assembled. The springs, retainers, and locks from the old heads were reused, everything else was new. The assembled heads were returned to my service dept. and installed on the car. The rocker arms and pushrods checked out OK and were reused. Cam and lifters looked OK and were left alone. New gaskets, head and header bolts, and an oil change finished it off. Fresh antifreeze too.

That was my experience, YMMV. Good luck.

383vett

I got new heads.

erick_e

Although they ordered bare heads (p/n 12578450) for my replacement, they also ordered new intake and exhaust valves and assembled them at the dealer.

rockinSeat

New heads, valves, etc. Reused rockers since they were fine. Heads assembled by local machine shop.

Oskee

Pkincy
My valves were so out of spec that they just replaced both heads with new replacement heads already assembled with all oem parts. I just hope that by GM honoring my warranty that I am not just rewinding the clock !!

bktmbill

Had mine replaced 1 year ago. 08z with 7700miles. Exhaust valve clearance >.010 on #1-4-5-7. yes car was loud { ticking noise} at 1800-2200rpm. Complete new set of heads were installed by dealer. They replaced exhaust rockers but reused intakes and pushrods also did cam inspection and said everything was ok. Car now has 13000 miles and runs strong and is very quiet. Biggest tell tale sign is how heavy the black goo on exhaust tips was compared to now. Will prob. do wiggle test in coming months and go from there.

2k Cobra

Mine too. Thanks Abel Chevrolet, Rich,Tony and their great Corvette mechanics for a fantastic job...

chrisfromalbany

so saying having alot of black goo on exhaust tips is bad sign? Never heard that before.

bktmbill

Just reporting my findings and experience. Maybe this is normal for some cars. Since heads were replaced its now just a grayish black soot that takes some elbow grease to remove compared to black gooey oil that used to be there.

wolf8218

My head castings, valves, and springs were replaced.

Wrong.

True, except for rocker arms and retainers. I saw them myself before they were put back in the car and they were fine.

vetteuphoria

As I recall, my car was being serviced just after 2k Cobra picked up his. Regarding mine, the replacement heads were sent bare. My original valves, springs, etc were inspected and swapped over by a local and trusted machine shop who had the valve stem/guide diameter specs. Seats were ground to match the valves and all guide measurements were checked on the new heads before assembly.

Now I know what everyone is referring to when they said it should sound like a sewing machine. Prior to getting the work done, my car has had a tick since new. I had just under 19,000 miles and, when inspected, 4 exhaust valve guides were found to be excessive: #2@.009, #3@.007, #4@.006 and #5@.008.

I only have just over 4,000 miles on the new heads since then, but it still sounds like a sewing machine. I'm extremely thankful for the crew at Abel.