pmathews

Just wondering if I should be concerned about the blowby that's coming from my oil filler tube? I have a cap on the tube, but it allows fumes and oil mist to escape. I have a good PVC valve that's pulling good vacuum, plus I have the other valve cover vented inside the air breather. I have 12k miles on the rebuilt engine, and it runs great with no oil consumption, but the fumes are annoying. I have great compression on all cylinders, 192 psi (+/- 2 psi).

I can smell the fumes while driving, and it's really bad after running the engine high revs. I was thinking about connecting the oil filler tube to the air breather with a hose, which should pull the fumes back into the carburetor, but is that a solution or am I just masking a more serious problem?

don71

How about using a factory style oil fill cap and trying that? Not trying to sound smart.

I'd be concerned too with what you describe as being too much blow by. The weakest link in any system will show symptoms first. Start there.

Is that baffle installed just under the fill tube? Sometimes they can be left out, so try to confirm that.

I'd try the cap first.

oldcutlass

Have you done a leak down test to see where it's coming from?

pmathews

Thanks guys

Baffle under the fill tube? Can I pull the tube and look inside to see this baffle, or is it located at the top near the cap?

I haven't done a leakdown, but I'll try that this weekend.

The old cap wasn't tight, and it blew off while hot rodding. Not a lot of pressure, it was pretty loose, but I'll see if I can replace that cap. Should it have some packing material inside?

redoldsman

It may sound silly but the PCV valve is not stuck is it?

cwb442

Not sure if it was rite or not but awhile backe I had the same issue. But had a high volume/high pressure oil pump. It was coming out of the dipstick too. So I plugged the oil fill tube and just put oil in through valve covers and no more issues.

pmathews

Thanks for the feedback guys.

My PCV valve is working good, you can feel the suction on PCV valve when you put your finger over the hole.

I'm running a standard oil pump, but that's something worth checking if you're pushing out your dipstick.

I like the idea of capping the oil filler tube and pouring oil into the valve cover hole. I think I'm going to try that (and do a leak down).

oldcutlass

The problem is if you close of 1 avenue for pressure to escape it will find another.