Weird engine blowing oil problem
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Weird engine blowing oil problem
My engine isn't all that weird but the problem is. I've checked all the basic things. I have a hose from the passenger side valve cover to the air cleaner base. The pcv valve is on the driver side and hooks to the carb base plate. All my other vacuum hoses are ok. There aren't that many.
If I just cruise around I get no oil but if I romp on the motor I get oil and it looks like it is coming out the top of the dipstick tube. When I'm running the motor with the crankcase breather and pcv off there is no smoke coming from the motor. That tellls me it is most likely not a blow by problem and besided the motor is fresh still.
The only thing I can think of is the pcv valve. I guess I could take it off and go drive with just a breather and see if that fixes it.
Anybody, any clues, please jump in.
If I just cruise around I get no oil but if I romp on the motor I get oil and it looks like it is coming out the top of the dipstick tube. When I'm running the motor with the crankcase breather and pcv off there is no smoke coming from the motor. That tellls me it is most likely not a blow by problem and besided the motor is fresh still.
The only thing I can think of is the pcv valve. I guess I could take it off and go drive with just a breather and see if that fixes it.
Anybody, any clues, please jump in.
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From: Kiefer, Northeastern Okla
Is it "pooling" on top of the timing chain cover? I had the same symptom, and it turned out to be the portion of intake manifold gasket that seals across the front of the lifter valley.
Pete
Pete
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It is blowing out the dip stick tube which makes the crankcase under pressure. "Romping" on the throttle produces more blowby which will pressurize the crankcase even with good rings unless the PCV valve evacuates the extra gases. Make sure the PCV hose is clear and the passage into the intake at the base of the carb is clear. Check all the hoses and the intake filter to make sure they are clear. They sometimes clog up with deposits. REPLACE the PCV valve, they are cheap and wear out. Just because they rattle does not mean they are operational.
BTW, it is not a weird problem, it has shown up many many times for over 40 years...
BTW, it is not a weird problem, it has shown up many many times for over 40 years...
Last edited by Torque1st; Nov 19, 2006 at 09:27 PM.
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I washed it all up and checked all my timing cover bolts and looked around the oil pan and the timing cover seal. It wasn't coming from there as far as I can tell.
I went to NAPA and got a new pcv valve. The old one looked pretty bad and had some serious gunk in the thang(thang is texan for the gidget inside the valve). I discussed it with them and they said both nips on the valve might need to be hooked up for it to work on my motor since I have a bit of a cam in it.
The valve has a lower nip that is slightly larger and one on top that is smaller. If you don't need the top one there is a small cap for it. I had capped the top one off on my old valve. I decided to go ahead and hook up the top port also and it seems to have fixed it but I'm not totally sure yet. I ran it up to 75 in second gear which is usually enough to blow oil out. This time no OIL! I'm going to run it for a while and keep checking but I'm hopefully optimistic.
I went to NAPA and got a new pcv valve. The old one looked pretty bad and had some serious gunk in the thang(thang is texan for the gidget inside the valve). I discussed it with them and they said both nips on the valve might need to be hooked up for it to work on my motor since I have a bit of a cam in it.
The valve has a lower nip that is slightly larger and one on top that is smaller. If you don't need the top one there is a small cap for it. I had capped the top one off on my old valve. I decided to go ahead and hook up the top port also and it seems to have fixed it but I'm not totally sure yet. I ran it up to 75 in second gear which is usually enough to blow oil out. This time no OIL! I'm going to run it for a while and keep checking but I'm hopefully optimistic.
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Joined: Sep 2001
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Naw, that's Kansan for no...
That top nib just needs to be capped, that is for connecting things like carbon fuel evaporator cannisters and all sorts of good EPA stuff. You don't want the crankcase vapors down in the line to the tranny modulator etc.
The PCV valves themselves wear out internally. The pintle valve wears and the orifice gets bigger but the biggest problem is that cheapo cheapo (that is my term for inexcusably poor) spring inside just fatigues and the valve essentially closes off under vacuum.
The other place the crud collects is right at the carb base where the hot fumes hit the intake air cooled carb. That connection and passage will fill up with crap.
Change out the PCV valve every year in the fall when you check the A-Freeze etc and winterize. The PCV valve is as important as any other valve in the carburetor.
That top nib just needs to be capped, that is for connecting things like carbon fuel evaporator cannisters and all sorts of good EPA stuff. You don't want the crankcase vapors down in the line to the tranny modulator etc.The PCV valves themselves wear out internally. The pintle valve wears and the orifice gets bigger but the biggest problem is that cheapo cheapo (that is my term for inexcusably poor) spring inside just fatigues and the valve essentially closes off under vacuum.
The other place the crud collects is right at the carb base where the hot fumes hit the intake air cooled carb. That connection and passage will fill up with crap.
Change out the PCV valve every year in the fall when you check the A-Freeze etc and winterize. The PCV valve is as important as any other valve in the carburetor.
