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Discussion Starter #1
So I've been chasing some oil leaks on my car after all the work I did. This may be useful for others.

As part of the work I did, I swapped out the plastic valve cover for an aluminum m56 cover. In round 1, I found that I'd failed to torque the cover on properly. The new seal washers were binding the bolts enough to meet the torque spec - but after a few heating cycles, I found that the bolts were pretty loose. I torqued it up and still found signs of leaks - mainly some oil burn off and oil leak signs.

So I pulled the cover completely last week and rtv'd both sides of the seal. Re-installed, torqued and got driving again. Seemed better!

After a longer drive - 2 hours out and back, I had some major leak signs going up-hill - namely a plume of oil smoke following me when I accelerated hard on the inclines. That's not good - and I drive alot of hills! The RTV'd seal had clearly failed me after some heat cycling and driving.

So I called around and found a shop that could put my cover on the belt sander and level it out. $50 later (cleaning + machine work) and I've got a trued valve cover. They showed me where it took effort to flatten out and it made alot of sense. I'm stuck for the moment until the new seals come in (I don't feel like hacking together a pcv with the plastic cover.)
 

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Well if rtv didnt help nothing on this earth will)))
Thats weird how could aluminum valve cover warp ( that has to be some intense heat or something)
Ive had plastic cover for 1 year of driving and after I overheated the engine like 3 times it started pissing out on my exhaust manifold( overheated like standing in 100F with no fans running))) and it blew up everything rad, expansion tank, thermostat, upper hose only lower hose survived it. So I tried rtv both sides and it did not help same issue after few cycles it developed a leak
Then I bought aluminum valve cover from an engine that never had an oil change in its life!!!!!!!! Took me 6 hours to clean out valve cover to the metal. I installed it without using any rtv and using victor reinz gasket that cost me 60 bucks. After driving no leaks developed. I had to take valve cover few more times to modify pcv system and I reused same gasket all the time because god damn thing is 60 bucks , meanwhile gasket for plastic cover is 15, never had a leak.
 

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Discussion Starter #3
It took forever, but I've found the root cause for my oil leak. The vacuum source for the PCV is clogged.
This is creating high positive pressure inside and forcing oil out the seal.
 

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Discussion Starter #5
the vacuum manifold is on top of the intake manifold.
I pulled the hose earlier, it was collapsing causing my problems. BMW hose will fix.
Sadly, it looks like friggin USPS left my new $80 hose in the wrong MAILBOX.

I am... less happy than I would have been this evening.
 

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Discussion Starter #6
Well my missing package appeared yesterday!
I capped off the second port on the vacuum manifold and installed the new BMW hose. Negative crankcrase pressure is back!
If I open the oil cap, the engine now stumbles as normal and no positive pressure is to be found.

I did my winter wheel swap and put a few miles on her running errands and things went well.

So, as much as I hate to say it, I have to suggest going with the BMW hose for the M546 valve cover conversion.
Grey RTV with the new gasket does a good job, though I may do the frickin thing one more time when it's warm again after all the high internal pressure caused leaks.
I'm going to let it ride over winter as RTV really needs a good 24 hours at mild temperatures to set.
 

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Discussion Starter #7
Figured I'd take a minute to confirm - the new hose took care of my issue.
My epic oil leaks are no longer happening and I've confirmed that I no longer have pressure build up in the crank case.
 

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Discussion Starter #9
I'm AFB - away from bimmer right now, I'm probably going to forget. Next time I install one, I'm going to only put grey RTV on the bottom so that the gasket can be reused. If I have a complaint with the metal VC it's the cost of the gasket so keeping them reusable is a very good idea.
I scored another M56 valve cover on my last junkyard run, so I'll be doing another one for my project engine. At this point I'm know that my block was swapped out by a PO and I suspect it was pretty worn based on the blowby and oil passage I've seen.
 
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