Positive Crankcase Pressure Problem-HELP PLEASE

[thetopcow]

Ok looking for your help. My dipstick is popping out and spewing oil, which should mean positive crankcase pressure, correct?

I did a compression check and got the following numbers:
1-157psi 2-160psi 3-160psi 4-155psi

I have read it could be bad rings, but wouldn't my compression be lower?

I have a brand new pcv valve.

My catch can is hooked to the left side of the "T" and then routed back to the intake after the MAF. The right side comes out of the "T" and back into the block. My catch can has really small holes, could this be causing a restriction and thus causing my problem?

I know this has been covered, but I found no completed threads with the information I am looking for.

[sunnys14]

Your compression looks good so the rings can't possibly be bad.

Check to see if the pcv hoses are clogged.

[GSXRJJordan]

Dipstick poppin out doesn't necessarily mean positive CC pressure - could just be vibration. As dipsticks get older, and dipstick tubes get bent, the vibration could wiggle the dipstick up and spray a little oil.

However, if you unscrew the oil fill cap and there's a pressure release, then you know you've got positive pressure under there. If there's no pressure release at the oil fill, just zip tie the dipstick down and you're set.

[VanduzerLancerES]

Dipstick poppin out doesn't necessarily mean positive CC pressure - could just be vibration. As dipsticks get older, and dipstick tubes get bent, the vibration could wiggle the dipstick up and spray a little oil.

However, if you unscrew the oil fill cap and there's a pressure release, then you know you've got positive pressure under there. If there's no pressure release at the oil fill, just zip tie the dipstick down and you're set.

Or check the rubber where the dip stick sets in the sleve. and if its bad theres the reason its poping out.. You could get a new dip stick with the sleve, i have one.. Turn your car on and hold your hand over the filler cap and then if you feel air coming out you have positive cc pressure, if theres oil in your hand after that, then your rings are bad.
Hope this helps.

[thetopcow]

ok well I did what the first two individual suggested. Without the dipstick popping out my car did run better and pulled much stronger without hesitation.

I then did what VanduzerLancerES said by coincidence. I took the oil filler cap off and I do have a decent volume of air coming out. How is it possible for me to have good compression and still have this much air coming out? So I then checked my Ford Ranger and it had air coming out of the filler cap, just not as much.

What do you guys think about the smallness of my Catch can holes? They are really small, like 1/4". What is a normal size catch can opening?

[slider2828]

This has been discussed..... Look for catch can setup I had this problem.

[thetopcow]

Well turns out I can have good compression and still have bad seals. So I need to do a leak down test. I will let you know how that turns out. Hoping it is valve seals but I bet it will be lower in the engine.

[jr_ss]

No matter what model engine, how new it is, or the type of breathing system you have on your V/C, you're going to have some air coming out of the oil fill hole when the engine is running... Think about it, you have pistons going up and down and an open galley in the front of the motor, there's going to be air movement, you just don't want too much of it.

[Z33dori]

yea every car is going to push air out of the valve cover.

my car is having this same problem. But it only started after my header melted the shitty tubing that came with my catch can.

[P_TAN]

I'm having the same issues and I've done comp and leak down tests on my engine, I did find one thing online that I'm gonna try on the weekend just thought i'd share.

Vibrant Performance ::. (http://vibrantperformance.com/catalog/product_info.php?osCsid=37c17552dd88b212c24df43361 4567f3&products_id=1243&cPath=1022_1035_1069)

[carnagexxxx]

How does it work?

[GSXRJJordan]

How does it work?

Looks like you weld the angled bung to the exhaust, put the scavenger in the crankcase, and connect them. As the exhaust rushes past the angled bung, it pulls air out of the crankcase, creating vacuum. Most race engines have something like this... I know all the Superbike motors I built did. Negative crankcase pressure can help free up some hp up top, and help with ultra-high revs.

[Matej]

Plugging the valve cover breather could cause similar symptoms.
Or even worse would be having the valve cover breather hooked up to the hotpipe/coldpipe on a turbo setup.