Questions about crankcase venting

[CarPsyco84]

http://www.maperformance.com/map-cra...acuum-kit.html

I've found these and the "krank vents". How do you fix the excess pressure from when the car is under boost, when there is no vacuum. I've disconnected the pcv and left both breathers open and it still builds up enough pressure to cause the turbo to puff blue between shifts under boost... I thought I saw a setup a while ago where a guy used a smog pump or something to draw out the air... or am I going crazy?

[iceminion]

Originally Posted by CarPsyco84

...I've disconnected the pcv and left both breathers open and it still builds up enough pressure to cause the turbo to puff blue between shifts

I think you are mis-diagnosing the issue here.

Crank case buildup is not bad for the car, however excessive pressure will cause leaks at and around the valve cover and oil cap...I can get into it for hours but lets not.

If you are experiencing blue smoke (oil) coming out your tail pipe, it cannot be from crank case, im sorry, its just not possible.

What is more likely is your turbo is leaking, talk to jhaan_dude, he rebuilds for cheap.

or, another possibility is oil is leaking down from leaky valve seals.

Or, the last thing to check is rings, if they are wron, oil may not be cleaned off he walls, and it is being burned.

Originally Posted by CarPsyco84

or am I going crazy?

join the club buddy

[blackrosenova400]

Uh, if it is the rings, then it is coming from the crankcase. It is entirely possible that after boosting and letting go of the throttle, crankcase pressure forces oil from the cylinder wall past the oil ring as the piston is on its way down on it intake stroke.

Good idea, check your spark plugs, if there clean move on from the crankcase idea. If your not satisfied heres what id do.

Lift up all drive tires off the ground, drive it and slowly get it in 5th gear at low rpm. Give it wide open throttle and let it go after redline, let it puff its smoke then immediatly shut off. Let it cool down. Remove the exhuast manifold and turbo. Look at your exhaust ports, if there clean then its your turbo.

With these cars, highly probable chance its the turbo. Make sure your air filter is clean. Alot of restriction can cause oil to get sucked into the intake tract though the compressor wheel.

[viridionplague]

first thing i would do is check your intake pipe for oil, and your intercooler pipes just after the turbo, any oil in those means bad turbo seals.

thats the first place i looked after i had the same problem, i ended up finding oil in my intercooler pipes, and in the intake tube, the turbo had bad seals.

[goodhart]

Mike, I thought I heard 4seasons69 say at the last fall dyno day that the oil rings were shot in the motor. I totally forgot about that until just now for some reason.

[s1ngletracker]

oil rings sound like the most likely possibility. You shouldn't have to do anything too crazy to vent crankcase pressure. The stock system for the most part does that just fine, unless you have a crazy setup.

[Halon]

Originally Posted by CarPsyco84

http://www.maperformance.com/map-cra...acuum-kit.html

I've found these and the "krank vents". How do you fix the excess pressure from when the car is under boost, when there is no vacuum. I've disconnected the pcv and left both breathers open and it still builds up enough pressure to cause the turbo to puff blue between shifts under boost... I thought I saw a setup a while ago where a guy used a smog pump or something to draw out the air... or am I going crazy?

When under boost, the vacuum source is your turbo inlet tube. That is why from the factory there is a hose going from the side of your valve cover, to your intake tube. That is how it "sucks" out crankcase pressure when under boost.

[CarPsyco84]

Originally Posted by goodhart

Mike, I thought I heard 4seasons69 say at the last fall dyno day that the oil rings were shot in the motor. I totally forgot about that until just now for some reason.

Not sure, still thinking its the turbo still, cause it smokes on cold starts, and im 100% Positive its the turbo and not the engine. With the 50 trim in it did not smoke at all, and with the 61 it smokes like a diesel just the wrong color... Went down to a .073 re-stricter and made a larger drain tube, hasn't changed anything... Garrett says +- 10 degrees off level for the CHRA is ok, but anybody ever had any issues with that before, I'm probably going to rotate it tomorrow anyway just to rule it out but I'm not real confident that will fix it.

[goodhart]

Maybe just put the 50 trim back on it then.

[sleepydsm]

Isnt this one of those rebuilt in the backyard turbos? (the 61) Thats why it's smoking, and your near new 50trim doesnt...

[blackrosenova400]

If it smokes at idle you can try this and only briefly.

Run the motor for a bit to lubricate the turbo. After that open up the wastegate completley to bypass all exhaust pressure off the turbo turbine. Then put something in the compressor wheel that wont hurt it, to stop the compressor wheel from rotating. Then go ahead and remove the feed from the turbo and plug the feed line. Run the car at idle and see if it still smokes.

Generally once oil has escaped the turbo, its too late and reducing oil to it wont help. I run a .110 restrictor on mine, with source oil pressure at 15 at idle and 80 psi at 8500 rpm.

[CarPsyco84]

Ok, I've gathered some more info. I tried a custom drain tube and now it does not smoke on cold starts anymore, only WOT shifts. Well, after putting a low pressure gauge in the dip stick tube I found out why. Damn thing made 3psi of pressure... in the crankcase, under full boost. pretty sure the limit for holset/garrett turbos is a fraction of 1psi... I made a custom catch can out of PVC, ran 3/8" line from both valve cover breathers and a 1/2" line to the intake. I'm for sure pushing coolant now too, so now I'm thinking not only pushing coolant but pushing air to the crank case? Did a sniff test on the coolant doesn't have Hydro carbons at idle.