Thread: Finding a way to Reduce Oily Blow By Gases

I was trying out the Carb Cleaner vacuum leak trick (spray carb cleaner on the tubes or connects and if the engine revs up then you have a leak).

Now when I sprayed some on the Idle controller screw, I saw some bubbles. I was wondering if thats a good thing or not...


Also the PCV Valve....

While idling, when I disconnected the hose that goes into the Intake Manifold, the car started to die until I would put my finger over the hose. While holding my finger over the hose, so the car wouldn't stall, I put my finger over the PCV valve, and a vacuum was not felt at all!

Now I replaced the PCV valve earlier this year, but my valve cover is of a high port and was kinda dirty with sludge, not as bad as my original one though haha. So I'm wondering if the valve cover's PCV passage way is dirty or something. I do get a lot of oil collected in my PCV oil catch can...

nice method de carbcleaner one.... i shal try it

You should have vacuum on the pcv valve out of the valvecover, but the engine will run a little funny when disconnected because pcv air is metered air (and you are venting it to atmosphere). As far as the bubbles, prob no worries there because the carb cleaner boils at a low temp so the bubbles could just be because it is a lil warm there.

I will take it off again and try it. I the PCV valve is not broken because I sometimes can hear it opening/closing hehe

With the Hose unplugged, that goes into the TB, the car just stalls. If I put my finger to cap off the hose, then the car idles normally. This is with the PCV valve wide open.

From what it seems like it idles dead because the Intake Manifold pressure becomes very low, thus it can't suck the air into the cylinders as easily...

But what I find interesting is, the fact that the car seemed to idle just fine with the hose capped off.

Bump, anyone else have any ideas?

With that hose unplugged, the car is sucking in extra air that wasn't measured at the MAF sensor, that causes it to stall. The engine has the ability to suck in massive amounts of air, even through that little hose. The A/F gets whacked, and the car stalls.

The crankcase doesn't really get too much blow-by pressure. So when the PCV is open, it's loosing a little metered air, but not a whole lot. Not near as much as the extra air sucked in when the intake manifold has an opening. So it's throwing off the A/F a little, but not enough to make it stumble and stall out. A lot of people run open breathers on their VCs without issues. That's pretty much the same concept.

Well people usually run breathers on the intake blow by side hehe, plus I've heard that oil drippage is usual, so for that reason I did this instead:




Now back to the PCV, I did notice that if I have the hose plugged up all right, and pinch it, the idle goes down, but doesn't stall.

I guess it probably is working right, just got me curious because the FSM said that there should be be a strong vacuum.

I did notice that one of the hoses for emissions, that seems like comes form the gas tank, probably fuel vapor line, it seemed like it was starting to age. So I will have to keep an eye out on it and maybe replace it.

Air should only be coming out of the PCV valve, look at the arrows on the pictures. It's intended to take in positive pressure from crankcase through the intake manifold to be burned in the engine.

Even the PCV Valve Operation chart shows all air flows out. That finger picture is screwy though.

Vadim, can't you just get a pressure tester and hook it up to the intake? You should hear where the leaks are coming from. Even on a NA motor I would think.

Well the thing is, It didn't seem like the air was coming out of the valve cover, now I did have latex gloves on (dentist ones), so maybe thats why I didn't feel it...

You know what, we just found a typo/mistake in that picture! I've just read it again and looked at the picture. What they mean is, take the PCV valve off the Valve Cover, and keep the hose plugged in. Then that would reduce the amount of air being sucked into the Intake Mani, thus still cause a vacuum when you put your finger over it.



Hmm interesting, I've noticed some places in the FSM where they have mentioned a pressure tester. Now just gotta fine one haha.