00PewterSS

iTrader: (3)

No idea if anyone here can help, but it is worth a try. We are in the middle of installing an LS4 from a salvage Monte Carlo. Today we pulled the xover pipe... this connects over the trans between exhaust manifolds. Oil was in the xover, maybe a half-cup. We removed the manifold and plugs on that bank. One plug was a bit fouled, but not so bad.

We have no idea where the oil came from. If the engine had an issue when it was running and dumped that much oil it would have burnt it. Tomorrow we will compression check it. The only idea I have is that maybe the junk yard put oil in the exhaust, but I dunno why they would do that.

Any ideas why there would be oil the exhaust?

Brian

spawne32

iTrader: (2)

I leakdown tested my LS4 on the stand, now I know that's not a great way to do it as the engines supposed to be hot, but I was able to identify issues on the stand with the heads that ultimately lead to me pulling the heads and having them reconditioned. DoD cylinders seemed to have issues with bad stem seals and most of the exhaust valve seats were shot with only 100km on the 243 heads. I was measuring less then 10% leakdown on all cylinders cold but all of them exhibited leakage past the exhaust valves exclusively, 2 cylinders being so bad that they were not able to be measured. It's worth a shot to see what you come up with, but getting the heads reconditioned is a good idea on those motors specifically because of the DOD. (and getting rid of the DoD itself, as the lifters blow)

00PewterSS

iTrader: (3)

Thanks it could be the valve seals... I hadn't considered that given the low mileage of this engine. But, it has been sitting now for 5 years.

We'll check it out tomorrow.

Brian