DelaWhere

Hey guys, I have what I believe to be a serious problem and would appreciate any advice you have.

First the the background: I have a beautiful '08 Z06 with roughly 9k miles, I purchased it at 2500mi from a dealer. At that time it already had a cam (with "proprietary" dimensions UGH!), a vararam, kooks/corsa, and a tune.

I enjoyed a NJMP track session with it, where the oil went as high as 310 deg; I later discovered this was because of the vararam and the hack job done to the radiator shroud. I considered changing the oil immediately after that run but since I was planning headwork I waited (I only accumulated about 250mi since anyhow). The oil has been changed regularly prior to this at well respected Chevy dealers, I was told it's incredibly difficult to drain a Z06's oil (no idea why I was told that... but nonetheless I never tried it myself until last weekend). Neither dealer mentioned a word about any issues.

Numerous shops and local friends checked it out in my search for a place to get headwork done, no one ever saw any reason for concern. I wanted to avoid the dreaded valve guide issue so heads were a high priority. I ended up doing the heads myself with the help of a few knowledgeable friends.

Sorry for the long read, I don't want to leave out any info that may help. So here's the problem: AFTER the new Advanced Induction heads were installed we changed the oil, (before starting it) this is of course the last step, we found metallic shavings on the LHS drain plug and chips on the FWD one (see photos). Frankly, I'm terrified, I had to drive the car home from my friend's garage (SLOWLY) but she hasn't moved since.

From talking to people I believe it's from the cam's lobes and I will be performing a compression test, then removing the valley cover and seeing if I can inspect the cam directly and I definitely will be sending the oil out for analysis ASAP.

Can anyone provide any tips/insight or comforting words for me?

JwT

Yikes..that's a lot of metal. Did you notice any unusual sounds while the motor was running? Like maybe the sound of a lifter taking a dump? I'm sure you'll get some sound advise. Worst case you have to tear it all back down, best case you clean off the magnets and check them every hundred miles or so and see it was left over debris from the head install. And I doubt you'll get any comforting words from this forum. Keep us posted.

DelaWhere

It sounded completely normal to leading up to the head work, on the ride home I convinced myself I was hearing new noises but that was most likely paranoia after seeing this. To be fair it is a super loud engine especially with the work done and I probably would've missed it anyway.

At this point I'm mentally (and financially) preparing to tear it all down, just hoping the thing can be saved without a full engine-out rebuild.

Thanks for the reply.

Mark2009

First off, always change the oil immediately anytime it gets that hot.

Second, the car had 2500 miles on it when you bought it and it had regular oil changes up to that point? Are you sure it had any oil changes at all?

Third, all things considered (aftermarket cam) I wouldn't sweat the metal too much at this point... change the oil and drive it if the oil analysis comes back without any huge red flags (like bearing material, which is non-magnetic). After about 1000 miles sample the oil again (this is probably what the lab will tell you too).

Fourth, anytime one has the heads off it is a good ideal to remove and inspect the lifters, and you can probably get a peek at a section of the cam lobes at this time too. Not a 100% inspection but better than nothing.

'06 Quicksilver Z06

As far as your next moves, the plan you outline above seems to be a sound plan.

On a side note, you mention that your heads were done by Advanced Induction.

What valves and guides did they use in your setup?

Rupert pupkin

I had the same thing happen when I changed my oil for the first time after I purchased the car. Ran it for 2k-3k miles and changed the oil again to get it ready for the winter and nothing was there. I'm 100% stock
Isn't think kind of normal, especially for the "break in" period?

DelaWhere

Bronze guides and SS valves (not sure about what brands/exact spec)

Also, I should've been more clear: this isn't the first oil change my car has had, it's the first I've done. It has 9k miles and has been to two different dealers for oil over the past couple years so I wouldn't call this break in wear. The cam has been in for about 6500miles as well.

Here's a question: if the shop that did the cam for the previous owner never replaced the lifters could that have lead to this? There was no evidence of the heads ever coming off prior to when I did it.

Thanks for the replies.
-Sean

Unreal

Replacing lifters on a low mileage car isn't common. Could it be junk left in the heads from the work? I doubt it? Pulling the valley plate to look at the cam is fairly easy. I would do a quick visual. If it doesn't show anything run it a bit longer and check to see if more comes out.

caker

Hi , I often found this type of metal on the mag drain plug on the pan side. Some of the shrapnel looked like bits of stripped thread material.
After changing the heads i found out it was valve seal material from turning valve springs.Three valve seals were hammered to bits, one was gone completly another broke in half and the last missing part of the base. Stock engine low mile car. Hope its nothing serious for you to repair.

'06 Quicksilver Z06

At 2500 miles, which was from the indication that you are giving was the mileage on the car when the cam was installed, it would not have been likely that they would have been looking to replace the lifters.

transAm-98

Cut the filter. That should be first order of business if you suspect something is going through your motor.

DelaWhere

Didn't think of that, I'll keep you guys posted with the results

rockinSeat

My plugs always look like that when I change the oil. In other threads where people ask the same question, its usually dismissed as normal with the solution being not to use a magnetic plug.

Its your car though.

AzDave47

The magnetic fuzz is normal, the metal chips on the first plug are not common.

rockinSeat

Apologies, I saw your pic on a dirty cell phone. Yeah, if its beyond fuzz, forget what I said. But kinda makes me wonder how big the stuff I was cleaning off my plugs was.

Mark2009

Very interesting. That's the second case of this reported here on the forum (in the case of the 2006 C6 Z06 below the car was a track rat with ~24K track miles on original stock heads ):

Mark2009

If the OP still has his original heads I would suggest removing the springs and inspecting the seals/seats illustrated above.

Since the car was cammed when he got it I would be interested to know if it had the original stock springs/seals/seats as well (would not be recommended for most aftermarket cams).

DelaWhere

I had AI port and clean my stock heads (didn't buy new ones outright). They said everything looked fine, they tested the springs and said they are still good (they are aftermarket but I'm not sure what type/spec), AI didn't mention anything about the seals or seats so I'm assuming they were okay.

caker

In the pics above of the valve seals,this is exactly what i found apon removal of the springs in my original heads.It was first detected at around 6600mi by a GM Garage. The seals and springs were replaced along with the eng oil pump cooler and lines. I found it again,at,12000mi, but one seal was already completly gone. After asking questions i was told it is by no means common but has been seen before. The recomended fix is the Katech PSI spring upgrade with the two piece valve seal/seat and Ti retainer.Parts are specific for oem guides or bronze guides.

I will add that my car was driven on track and used for what it was built for. It is an 06......

Todd

Mark2009

Two things could be going on with the stock spring seats (not to hijack the thread too much):

1. I doubt the OEM spring seats are hardened steel. All aftermarket spring seats I've seen for sale are advertised as hardened steel. This makes me think they would stand up better than the OEM seats.

2. The OEM valve spring is run very close to coil bind... perhaps as close as .050" depending on who is doing the measuring and how. Normally .050 is desired when dealing with a performance shop that measures everything individually. However, spring manufacturers recommend running no closer than .050 to coil bind and in a mass production situation -- like the LS7 heads -- we really don't know where the tolerance stack up leads to and using .050 as a spec/target is really leaving no room for production line error (which, in the opinion of some, we are seeing in these heads).

So, to sum up, the springs might be running too close to bind and that could be causing the damage we see to the OEM spring seats, or the OEM seat could simply be too 'weak' (unhardened) to stand up to normal LS7 operating loads. All this assuming no repeated driver error (over-revving the engine and floating/bouncing the valves, which would be hard on the spring seats (and most everything else in the valvetrain)).