Background: I'm using a dual OCC and seldom go into max boost conditions for any length of time. My MCS R56 has a pair of Fuel Cut Defenders, and boost is set to about 25psi (with a remote AP tune). I recently (about 1K miles ago) replaced the valve cover because the PCV was not relieving crankcase pressure at positive manifold pressure.

Last week, at a Hooked On Driving event at MiniThunder V, I developed a serious oil leak during my second of five series of runs --- lots of high boost driving. A quick look showed a warped valve cover near the un-shielded turbo, allowing oil to escape. I finished the day watching friends have fun.

I had extra oil with me so I decided to drive it home instead of towing / hauling. During my drive home (200 + miles over the Sierra Nevada mountains) I noted that the oil loss was worst during uphill driving --- slightly positive manifold pressure. Probably another shot PCV.

My concern now is that the PCV is not designed to withstand 25psi. As a fix, I'm going to block the rear PCV hose connection, at both the valve cover and the manifold. Then I'm going to try to remove the PCV mechanism from the valve cover, leaving the one OCC connection in place, with no valve controls. I'll do this on my original valve cover --- the one not warped. I'll use the warped one as a learning tool for figuring out what to remove.

Other, non-related work is in progress, so this PCV solution's effectiveness won't be known for a couple months.

If anyone has knowledge about our PCV system operation / limits, and is willing to share it --- PLEASE?

 

Have you read Thepenl's thread over on MiniTorque? Lot's of technical details including some PCV discussion.

http://www.minitorque.com/forum/f272...nls-r56-25947/

Stupid question... but why do you think the PCV system is to blame vs the warped valve cover?

Also I thought there were a couple posts where someone blocked the PCV and it led to issues of oil being pushed past the turbo... need to dig those up.

 

Thanks for the link, I'll bookmark it. Kinda lengthy to read now. Looks really interesting.

My warped valve cover is obviously caused by the un-shielded turbo. I believe a faulty PCV system is making the leak worse.

I've done some of the posting about oil leaks from the turbo caused by high crankcase pressure. Took me awhile to realize it was a faulty PCV. Now, I'm trying to understand why the PCV fails.

 

Why not block the manifold and just run both PCV vents VTA? I've been running this setup for a couple months so far, no problems. I'm running a stock motor though, so it's just to prevent carbon on the intake valves.

I'm pretty sure Thepenl runs this same setup but the hoses go to a twin OCC before venting to atmosphere.