Hey guys,

I was giving my buddy a hand this wknd to help him figure out why he's getting misfile codes. I pulled the plugs on his heads/cam LS2 and found that the plugs from #1 & #4 cylinders were covered in oil and carbon. #4 was the worse. Those plugs have only been on there for about 1k miles. The engine runs fine but he's just getting misfire codes.

I'm thinking that maybe the oil control rings are bad or there might be some bad valve guides. Before I tear everything apart I wanted to get a few opinions first.

I was thinking of performing a leak-down test first to eleminate the possibility of bad rings. Then if that turns out ok I was thinking of then removing the heads for inspection.

What do you guys think?

Thanks in advance.

 

I think it's the valve guides.

 

i agree, might be the valve guides

 

How many miles on the Heads?HOw many miles on short block? Also you said its a head cam motor,did he get the pushrods the right length? just going thru causes on why the valve guides may be bad?If thats what it is.

 

The motor has about 61K miles and 2-3K miles on the heads/cam package. It's funny you mention the pushrods. I was thinking the same thing. 2 wknds ago I told him that his motor ticks a lot and maybe he needs longer pushrods. I think he has 7.350". I think he needs 7.400". I'm giong to pull off the valve covers this wknd and check to make sure.

First I'll check the compression just to eliminate the rings from being bad. I doubt the rings are bad. This motor has only seen nitrous a few times and that was it. It never even made a complete pass on nitrous.

 

UPDATE:

I finally had time to run a leak-down test on my buddies LS2. All cylinders are 7-14% compression loss which is acceptable. We'll be pulling the heads off this week to check the valve guides.