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So here is the story... I bought a 2007 z06 last week that was built by a fairly well known shop in texas. It was running fine, I think, but it had been a while since the car was used much. The owner that I purchased the car from had only put a few thousand miles on the car over the last couple of years. He had not changed the oil since installing a new ARE dry sump system a few years back. Not good, I know. I immediately changed the oil and this is what I found in the pan. Who can identify the various potential problems?
Looks like mayhem under the valve covers. The finely-wound spring and rubber pieces are the remnants of one or more valve stem seals. The other metallic detritus is of even greater concern. Time to remove the covers and inspect.
Ditto, game over man, since someone did not check the amount of clearance on the valves with higher lift cam, and they where crashing down on the valve seals to take them out (or could be that the valve stems to valve guides where not check for excess lash, and that took the seals out instead). Also, seeing some other seals in the mix as well, so now it's time to pull and tear the motor down to figure out what the hell is going on for that many seals to fail in the first place.
Also, with the amount of debris, need to replace the engine oil cooler and lines, since your never going to flush all the trash out of them, and what is left in them and reused, it going to find it way back into the motor again.
My guess, the old owner only drove the car for a few thousands miles when he found all the debris himself, and why the car sat/was sold off instead.
Yeah, it's bad, and you will have to do some exploratory surgery to get a better feel for the damage, but don't lose sight of the big picture. You can now get a new LS7 crate engine for $10,900. LS7 Crate Engine
The car was running fine the day prior to the oil change. I'm hopeful that the damage to the bottom end is limited. Currently planning on pulling the motor and going through it to assess the damage.
A little update: The motor is out. There was some ware on the cam bearings, main bearings, and rod bearings. Those are all being replaced. The block is currently at a machine shop getting line honed. The crank is being polished. I have some questions about the valve guides and wether or not they are stock. The work was originally done by LG motorsports, but the valve springs were replaced again by the previous owner. The heads have been ported and the exhaust valves were replaced by LG when the cam was swapped. LG could not guarantee that the valve guides were addressed at that time. That would have been around 2012ish. Here are some pics, what do you all think?
Just make sure your running solid SS valves, and since the valve guides are in question, now would be the time to have them replaced since the heads are off and stripped down. Hence valves still need to be lapped back in to clean up the seats, so no extra money saving on that after part, once the guides are replaced and reamed isntead.
Bottom line, LG know how to build a engine, and if they have anything in question on the rebuild, favor to what they think will be best in the end. Hence trying to save a few bucks during the build, to end with another engine failure, is no savings in the end.
Yeah, it's bad, and you will have to do some exploratory surgery to get a better feel for the damage, but don't lose sight of the big picture. You can now get a new LS7 crate engine for $10,900. LS7 Crate Engine
Lets play a game....
