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Discussion Starter #1
PVC crank case vent tube
Does someone have a direction and how it operates the PVC crankcase vent tube.
I believe it goes toward the intake for flow and is checked flow toward the turbo.
Another wards if there is vacuum on the intake it will not allow it to pull from the turbo.
But when the turbo gets engaged, it over comes the check valve in the tube and puts forced air toward the intake?
Sorry for my ignorant's i want to be sure i am not pressurizing my crankcase and push oil out my rear main seal.
just confused in how it works, including the turbo?
Thanks in advance
 

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While the PCV hose looks like its going into the intake manifold actually vents into the camshaft cover with oil holes in the head that go clear down to the crankcase.

Is a check valve in that hose, kind of pricey that only lets air pass toward the inlet of the turbo and is shared with the air coming in from the air cleaner. But this hose is of the venturi type where air passing over it creates a vacuum. Would be a very bad idea to put it at the outlet of the turbo because of the high positive pressure.

Ha, as far as this goes not sure if the inlet is a good idea either, because as the engine wears and carbons up, get more of that nasty blowby with more junk in that PCV hose that gums up the vane in the throttle body. Ford was doing this for years, and cleaning the TB had to be done frequently. Honda was returning it to the base of the TB, a far better place. Further complicated in the Cruze by use throttle by wire.

For this reason, tossing a can of Seafoam in a full tank of gas every 5-6,000 miles or so.

By connecting a vacuum gauge to the inlet of the dipstick tube, should read 20"/Hg at idle as sea level. This will drop about 1.1" for each thousand feet above sea level. If low, you will generate a P071 code.
 

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Discussion Starter #3 (Edited)
OK I GUESS THAT EXPLAINS THE FUNCTION BUT I AM UNCLEAR ON THE PURPOSE of it. also if the turbo isn't functioning correctly what problems can it cause?
Can it cause a rear main to leak a little.
I have changed the rear main seal twice and i sealed the flex plate bolts with sealant.
I get a drop of oil every 500 miles.
Just wondering if i have other vacuum problems, i checked the valve cover pvc and it is not leaking i believe i have good vacuum.
The car seems to be idling ok.
I do have vacuum on my dip stick and i believe it is at least 20HG on idle , but i will check it.
Thanks for any added info
 

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Ha, with dealing with GM rope rear seals for 30 some odd years, and a rope is the precise word for it, looked like a piece of cut off clothes line.

With other GM engines, rear neoprene seal was falsely blamed for leaks, Used RTV around the back of that seal that was the cause. Trying to learn this about the 1.4L engine, but doesn't have main bearing caps, but like a tie crankcase between the block and the crankcase that can be a source of leaks. Rear seal fits in there.

With other high mileage vehicles with real neoprene seal, leaks. got by with Lucas Engine oil seal treatment. Really a PITA to remove a transaxle to replace this seal.

My 454 CID developed a rear seal leak, not very many miles on it, but is 33 years old, Lucas was nice to me.

I assume you are only using dexos approved oil in your Cruze, conventional oils can cause leaks.

Really doubt anything dealing the turbo is your problem.
 

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Yeah, still have that Chinese puzzle finger pulling tool somewhere around here for pulling that rope around the top. Were never suppose to cut it, but jam it in somehow. With luck, would last maybe 10,000 miles.

Would never fill the oil to the full mark, it would quickly leak out to the add mark. Always had a piece of cardboard on the garage floor. A close friend has a 66 Corvette, with the same piece of cardboard under it.

78 Fleetwood was the last car with a rope seal, but later got a 92 DeVille with a neoprene seal that started to leak. I did purchase a new rear seal, but what a job that would be dropping an AT transaxle. Tried Lucas engine seal conditioner just once, and it never leaked again, talking about another 60K miles of driving.

Got in my motorhome this spring, hit the brake pedal and never came back up again. Manual says to remove the Hydroboost and clean it. Ha, that thing is jammed between the frame and the motorhome body. So I removed the power steering fluid and filled it with Lucas power steering conditioner. Started the engine, and in less than two minutes was working fine again.

Thanks God for Lucas, but really doubt if this stuff would work with a rope seal.
 
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