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Ooops - that's wrong Posted by Ari [Email] ![]() ![]() In Reply to: Re: How can a faulty turbo pressurise the crankcase?, Peter Mac, Sat, 15 Mar 2008 20:50:26 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Can you get some pressure from the turbo? Yes. But not a lot. It would need to leak pressure into a pressurized oil line. Not likely.
But you're also going to get some blowby the rings, and that WILL pressurize the crankcase. There is a very good reason why the crankcase is ventilated from the valve cover - if you block that off, you'll pressurize the crank. Rings aren't perfect - that pressure has to go somewhere. And those pistons going up and down also pump air. Yes, if it were prefectly sealed and the pistons were perfect, it would just flow back and forth, but again, it isn't perfect.
In the old days, they just vented the valve cover to the air. But that pushed some exhaust gas and oil vapor into the air. Nowdays it gets vented back into the intake to get burned.
You seem to really want to blame the turbo. But blocking off the vent from the valve cover will pressurize the system. Reconnect the hose, make sure you've got a good one-way valve in there (arrow pointing away from the valve cover), and all should be right.
posted by 75.58.11...
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