Engine/Transmission (1994 - 1998) Blow-by

[CWeidenkeller]

Well, 7K after the head gasket change and it's still blowing smoke out of the draft tube. Not near as bad as it was, but still there. Sometimes I can smell the oil smoke at idle. But it still doesn't burn oil, and all temps are still in the normal range. Still runs great. Anybody know what is acceptable blow-by, and how to check it? Might advancing the timing help (I know this will increase cylinder pressures, but I'm gonna do it anyhow)?



Talked to a lot of sharp folks, but I never did get it tracked down (a lot of might be's..... ).



Somebody throw me a bone... ... .





'96 CCLB 4X4, Slushbox, 4. 5" lift, 37" swampers, #4 plate, 3K GSK, AFE filter, $PA, blows smoke out both ends!

 

[T. Baker]

Blow by is just about always caused by pressure leaking by the piston. A new head gasket wouldn't help that unless it was leaking into the pushrod holes. The only thing that will fix blow by is to rebore and put in new pistons and rings. You might get away with honing and new rings if it is just very light scoring and you don't have a cracked piston. Unless you want to rebuild your engine you will have to live with it. Make sure your air cleaner and piping are doing their job. Did you inspect and mesure your bores and look at the pistons when the head was off?

 

[illflem]

If it's not using oil why worry about it? I've always heard that if you can't hold your thumb over the end of the hose at idle then something's wrong. Check valve adjustment. You never notice blowby on a gasser because it goes back into the intake.