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Thread: Boost in Crankcase?

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Posts: 11-19 of 19
2012-04-08 12:56:04
#11
Try changing the PCV valve. I had a similar issue with pressure coming out of the dip stick, and it turned out to be the PCV
2012-04-08 15:09:40
#12
Originally Posted by morgans432
im not so sure about this one...


I've seen this happen with clogged PCV valves, but not generally with silicon sealant. Usually a rubber or cork gasket. But you have to admire the amount of force being applied on such a large area. The dipstick will pop out before blowing out any of the gaskets on the nissan. I guess the valve cover gasket could have issues, though I haven't seen it. But I concur, blowing out the oil pan sealant probably isn't going to happen.
2012-04-08 16:13:46
#13
check the pcv valve. I checked mine recently and found it did not always seal 100% all the time. I tested it 5 times and three times it was leaking some air.
2012-04-08 18:30:05
#14
could be broken ringlands...it wont show on a compression test, but will show on a leakdown or pressure test, a car will sometimes drive almost normal with the issue...seeing how you are pressurizing the crankcase, it could be more than what you're thinking but hopefully it is a simple inexpensive fix
2012-04-08 19:51:08
#15
Thats the truth.

My buddies nx went over a year and another 25k miles on broken ring lands and boost. Only way you could tell at first was it was blowing oil and smoke out the breather on the valve cover. As the wear got worse it started sounding like a subaru and started showing up on the compression numbers as the cylinder wall became scored to hell. Even then still kept on running, run after run, abuse after abuse. It got to the point it was just soo bad it was time for a new motor.

Vadim, easiest way to tell if you have bad lands is to remove the breather line from the valve cover and see if your getting any pressure out of there or smoke while the car is running and reving up in neutral. Pretty easy.
2012-04-08 20:00:19
#16
I've always had air come out of the breather hose, or oil cap, when removed with engine running. But I don't get any oil or oil vapor out. I vent to atmosphere now and it is still oil free.
2012-04-08 20:34:56
#17
Check the PCV valve, it was functioning just fine when I put mouth pressure to it and it didn't leak, though I will replace just in case.

I did see a slight puff of blue smoke on a stop light, but I did free reved the engine right before hand.
2012-04-09 08:09:14
#18
It will feel like there is air coming out but its really a pulsation of vaccuum. Way to tell is just cap the breather with your thumb and see if the crank case builds up suction. Hold your thumb on there for 5-10 seconds and then release. If your running a PCV valve it should build a suction if you dont have excessive blowby. Even my last motor that had excessive blowby would still build up a Vac at idle.
2012-04-10 06:07:36
#19
Did a leakdown test today. I tried to do 100psi, but would have very low numbers...




Turns out the spark plus seal on my summit tester was horrible and it was leaking air through the spark plug holes.


Turned it down to the point where it wasn't audibly leaking out of the spark plug holes, cylinders 1-3


Cylinder 4 slightly lower
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