[RichardGoller]

So I did a wet compression test on a cylinder after I did a leakdown test and it come out like 40%. So I thought and still think it's piston rings. It's not consuming oil and doesn't smoke, just idles rough. I took the manifolds off, still can't hear anything from either side, so I still don't think it's valves like some suggested, would be weird too because I don't know how oil would seal a bad valve, maybe if it wasn't seated. I'm just about to drop the oil pan since I was commited to change rings while engine still in the car, would be good opportunity to listen to the air hissing while the pan is off. Even if it does turn out to be a head issue, do you think it's best to replace rings and rod bearings since it's a matter of taking the pistons out and putting new rings on and since I'm there might as well swap rod bearings.

[Saico]

What is your engine and what are the compression values?

[RichardGoller]

Originally Posted by Saico

What is your engine and what are the compression values?

N52B30, every cylinder come out at around 250 psi, cylinder 4 is at 200 psi. Put some oil in, went up to around 250

[Saico]

Seems quite obvious it's rings. For the bearings - have a look and see if they need changing, I wouldn't change good bearings. They rarely ever fail on N52s.