Hello everyone, I just made this account so i can post my concern. I have a 2009 Pontiac G8 GT. The DOD system failed on me and the lifter collapsed on cylinder 6. While we were diagnosing this issue, we also noticed the lifter accross over on cylinder 5 was rubbing against the cam and we saw metal shavings from it (will post photo of it rubbing and photo of the damaged lifter). The rest of the lifters looked pretty fine to me. We took everything apart and got a TS stage 2 cam, ls7 lifters, resurfaced heads and hot tanked them, installed 660 TS dual springs, high performance oil pump, and new tensioner old one was bad. We were ready to put everything back together and we had a tune day coming up as well until we noticed these scratches on the cylinder walls. I could barely feel the scratches on 6 and my fingernail does not get caught but for cylinder 5 i could feel them a bit more and when I run my nail on it it doesnt catch going fast but if I go over it real slow it does get caught. I called multiple machine shops and I explained to them and obviously most of them would recommend a rebuild and go the sage route but I have spent so much on this car already and now my question is will this be a major issue? The cylinders still hold compression. What should I look out for (signs?) if I put it back together and run it? What’s the worst that can happen? I will post picture of the scratches and the first picture is cylinder 6, and the second photo of the scratches is cylinder 5. Thank you please share your opinions and thoughts on

 

I would definitely pull the pistons and check them. I would also run a hone through those cylinders. Looks like the piston was dragging something, hopefully not pieces of the piston.

 

I personally would measure compression on all cylinders and see what that looks like

 

Compression check and leak down test. If they are decent, leave it alone, BUT, with the metal from the cam I think the motor needs to come apart anyways.

 

If you have metal shavings it would make the most sense to do it right now. It will be significantly more expensive if you gamble and lose which I would say is at least 50/50.

 

With the amount of metal that came off the cam and lifters, that engine needs to come all the way apart. Doing anything less will be a grenade with the pin pulled.

 

Considering that you can see the scratches but not quite feel them, you may be okay.

At minimum, the cylinders would definitely benefit from a hone job.

 

Run it as is: Best case, constantly worry about it.
Worst case: pull it down again and repair the additional damage done in the meantime.
You already have it halfway apart with the heads off anyway.
In context, bearings and gaskets are cheap.
Give the cylinders a really quick hone, replace the rings, clean all the metal debris out of the block...
Do it once the right way, good to go.

 

it would be a shame to put it all together to do a leak test and it failed. Ur back to square one, tearing it back down again or im i missing something? Im not the sharpest tool on a murderer.

 

Throw it together and run it! I have an LS7 that has 3 or 4 cylinders like this. Thanks Comp, for the junk "trunnion upgrade", that puked metal powder thru my engine, and also ruined a good Melling 10296!!!. I use no oil, and the car runs like a scalded dog!! Actually, it runs so good, I've seriously gained respect for Lear, the GM vendor who built the seats, because the seat backs haven't broken.....yet. I am sans cats, so I'd see smoke if there was much oil getting past the rings. If you're going for a world's record speed in the 1/4 mile, you may want to freshen it up. If you aren't using oil (if you are still running cats, they will hide a lot of oil smoke.), and it's a street/strip car, I'd run it. My .02......

EDIT: Get a good, VERY GOOD, rare earth magnetic drain plug. It will help cleanse the internals as you drive. That's how I found out my Comp trunnions were junk. That and the great forum members here. Also, have a good look at your oil pump. It may be all scored up even worse than the cylinders....

 

I would probably be thinking differently than my previous post if I was still in the work force, and a young man again. Young being under 50 years old. I'm 68 years old, and retired. I was like many guys here when I was younger. If that was the case, I'd yank the damn thing, clean it up, rebuild it, assemble it, and live happily ever after, I hope!! But in the real world, that engine is going to come out. Either now, or eventually. You've got nothing to lose running it now. If it uses oil, which you say it does not, pull it out now. If it doesn't, like I said, unless you're shooting for an NHRA National record, run it 'til it has to come out......

 

Fix it right.