Oil in intake manifold and blowby through valve covers
07-26-2007, 08:29 AM
#1
Oil in intake manifold and blowby through valve covers My fuel pump went out a few weeks ago, and I managed to limp home. I have replaced the pump, and it works fine. However, ever since that evening I have had blowby through my valve covers (one side has a breather cap on it). Now I am getting oil on my MAF. I though it might be the turbo, so I took all the intake tubes off and checked them. They are clean. I then took the elbow off the TB and checked inside the blades. Sure enough, there is an oil film there. What could be causing this? It is most likely associated with the blowby through the valve covers.
Thanks.
Thanks.
07-26-2007, 08:57 AM
#4
I managed to get it started, but it would only run at high revs. So I kept the revs up by shifting manually and annoying anyone who might pass by. I really had no choice, I was out in the country, in the middle of nowhere, no fuel pressure gauge, so I just did the best I could and made it home.
Further testing showed me it was fuel pressure that was the problem, but only after running about two hours. A real PITA to track down.
Further testing showed me it was fuel pressure that was the problem, but only after running about two hours. A real PITA to track down.
07-26-2007, 09:04 AM
#6
Originally Posted by Hot94Z28
Comes from the tube that leads to your valve cover. You can put a push in breather on and plug the hole on the TB. Or you can put an inline filter in.
Thanks.
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07-26-2007, 09:07 AM
#8
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Originally Posted by koolaid_kid
Well, I looked at the TB and did not see a tube running to the valve cover. Where is it located on the TB?
Thanks.
Thanks.
07-26-2007, 09:14 AM
#10
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Well I'm no expert but that was my first inclination since you were boosted. I would buy a compression tester and you might be able to narrow it down to a single cylinder. You are supposed to be able to tell if it's a ring or a valve by the way it reads and leaks down. Then you can pour oil in the spark plug hole and see if it changes anything--you'd just have to read the directions. Maybe you can just get away with a head getting reconditioned (best case scenario).
07-26-2007, 09:24 AM
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Originally Posted by koolaid_kid
Well, I looked at the TB and did not see a tube running to the valve cover. Where is it located on the TB?
Thanks.
Thanks.
07-26-2007, 09:56 AM
#14
Originally Posted by dhdenney
Well I'm no expert but that was my first inclination since you were boosted. I would buy a compression tester and you might be able to narrow it down to a single cylinder. You are supposed to be able to tell if it's a ring or a valve by the way it reads and leaks down. Then you can pour oil in the spark plug hole and see if it changes anything--you'd just have to read the directions. Maybe you can just get away with a head getting reconditioned (best case scenario).
07-26-2007, 10:38 AM
#16
Originally Posted by dhdenney
You were just hoping that wasn't it?
I have never seen it so bad that it went into the intake manifold and through to the MAF. Last year I replaced an oil check valve on the turbo, which was also oiling the MAF. That's why I took the intake tubing all apart. But they were squeaky clean.
Thinking it through, it happened during a lean condition, and it is leaking into the intake manifold. Both strong indicators that it is the valves. Fortunately, it only seems to oil the MAF when I go into boost, so if I can prove to myself that it is the valves, then I will just not go into boost until I fix it.
BTW, I didn't go into boost on the way home, I just had to keep the RPMs up. Just an FYI, not that it matters. Motor is still hurt, and looks at me pathetically every time I go out to the garage.
07-26-2007, 03:09 PM
#18
Motor is 100% stock.
I really don't want to make any more power until the rotating assembly is forged.
Since it only has 37k miles, I was hoping to wait a while to do that.
What kind of damage do you think would occur by driving it with burned valves? Say, 1000 miles.
OTOH, if I waited until the season is over, say November, I could possible pull the motor and do it all right then. Just thinking out loud.
At that point, of course, the tranny and diff become subject to sudden suicide, another 5k down the fbody drain.
I really don't want to make any more power until the rotating assembly is forged.
Since it only has 37k miles, I was hoping to wait a while to do that.
What kind of damage do you think would occur by driving it with burned valves? Say, 1000 miles.
OTOH, if I waited until the season is over, say November, I could possible pull the motor and do it all right then. Just thinking out loud.
At that point, of course, the tranny and diff become subject to sudden suicide, another 5k down the fbody drain.
07-26-2007, 05:19 PM
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technically i dont think driving with burned valves would cause any major problems... mostly loss of power. i could be wrong... but i believe if i had something to drive, i would definately do that. and just out of curiousity, how is it that your pcv system is plugged off... i wouldnt think that was a great idea being that your car is boosted. with my experience, the boost blowby would cause the dipstick to blow out, or press seals out of the motor from excessive crankcase pressure. i was exposed to working on an STS charged GTO before, and i do recall that crankcase pressure was an issue, but that was i guess about 1.5 to 2 years ago. just my two cents. correct me if i am wrong please though...