ls1
10 Second Club
Joined: Jan 2010
Posts: 2,317
Likes: 20
From: Hurley, VA
If you have oil in 7 and still low compression you've got a hole in a piston or the head. Do a dry compression check then pour enough oil in the cylinder to cover the piston and check again if it comes up with oil its ring related. Ive had rings stuck before showing 0 compression and shoot to 150 with a little oil.
man I really don't like that, when engines start spilling oil in any location. Piston/ring is painful of course because now you have to dismantle the entire engine for one silly part. And then it might not even be truly fixed once you finish. What caused it to begin with is still maybe running rampant...
You would have to pull the heads from a new engine anyways if you don't know the history. If you have no expensive parts inside it, pretend this engine is your new engine. Pull the heads and look inside, and if you don't like what you see do what you would do in the other case: go look for a better candidate. While you do that, continue searching inside your damaged engine for clues, examine every part. If damage is minimal obviously continue using it. I am only saying do not get hung up on expensive extensive repairs in unknown circumstances unless you are fully aware of how your engine was used (if you owned it from day 1, for example, you would be much less likely to replace it, knowing how it was treated).
You would have to pull the heads from a new engine anyways if you don't know the history. If you have no expensive parts inside it, pretend this engine is your new engine. Pull the heads and look inside, and if you don't like what you see do what you would do in the other case: go look for a better candidate. While you do that, continue searching inside your damaged engine for clues, examine every part. If damage is minimal obviously continue using it. I am only saying do not get hung up on expensive extensive repairs in unknown circumstances unless you are fully aware of how your engine was used (if you owned it from day 1, for example, you would be much less likely to replace it, knowing how it was treated).
Cyl 7 issues usually mean lifted ring land on ls1s.
5 and 7 together would point to head gasket normally. Could be valve stem seal related or valve related also.
3 places to look. cyl leakdown and small camera in bore would show more.
5 and 7 together would point to head gasket normally. Could be valve stem seal related or valve related also.
3 places to look. cyl leakdown and small camera in bore would show more.
