Valve Cover Leak?

[delirium330]

99% sure this is a classic valve cover leak, but figured worth getting a confirmation before I tackle this job. Was getting a burning smell at cold start... and upon inspection saw this.

I think I still have some Loctite RTV 598 from my last BMW valve cover job...

[Mvy]

Thats it. I just got the same thing starting finally after 10 years. You might want to open the oil cap and check to see how the inside of the cover looks. Mine is all gross and mustardy yellow with chunks falling off. No real worry of engine damage as the oil filter picks it up but its time for new covers with the gasket for me at my next opportunity to remove the super charger.

[shimmy23]

Seems like the mustardy and peeling cover issue is common. Is it recommended to just replace the cover?

[Mvy]

Originally Posted by shimmy23

Seems like the mustardy and peeling cover issue is common. Is it recommended to just replace the cover?

Yes. Its expensive but it takes care of the leak and mustard all at once. I think they are 650 each.

[shimmy23]

Originally Posted by Mvy

Yes. Its expensive but it takes care of the leak and mustard all at once. I think they are 650 each.

I’ll have to do this eventually. I’ve noticed some leakage. Also read that the early covers can warp?

[delirium330]

Yellow mustard build up is interesting. I had a ton of mustard build up on my 2005 330i ZHP, was thick like mayo and I spent 2 hours trying to clean it up before putting the valve cover back on.

[pbonsalb]

I’d probably clean it and see how long it takes to return. Obviously it won’t fix itself but it may not need immediate attention.

[Mvy]

Originally Posted by pbonsalb

I’d probably clean it and see how long it takes to return. Obviously it won’t fix itself but it may not need immediate attention.

I think its a coating inside that flakes off the magnesium valve cover. I think they put the coating on to protect it but the heat cycles makes it fall off. I am not sure if blasting and re coating it is the best idea, or if just blasting it clean and adding a new gasket would work. I am just leaning towards replacing as the time it will take to clean it up then recoat is going to cost me close to just replacing.

[deansbimmer]

The underside isn't fully coated like the exterior. The mfg coats the gasket grooves and any overspray into the underside is all it gets. It doesn't take much time for it to start deteriorating.

Two new covers are over $1200. Most people spend some time cleaning them up and reusing them. Take extra care to clean and smooth the gasket sealing grooves. I use a stainless wheel brush on a rotary tool.

[motion732]

How bad for the car is it? Mine kinda weeps over a few hundred miles and I just wipe it off

[BimmerMan33]

$1200 for a pair of valve covers is too much. I would rather get them sandblasted & powder coated matte red or some other interesting color on the outside, would not coat/color the inside so there would be none to flake off, shouldn't cost over $300 and look cool too!

[pbonsalb]

Originally Posted by Mvy

I think its a coating inside that flakes off the magnesium valve cover. I think they put the coating on to protect it but the heat cycles makes it fall off. I am not sure if blasting and re coating it is the best idea, or if just blasting it clean and adding a new gasket would work. I am just leaning towards replacing as the time it will take to clean it up then recoat is going to cost me close to just replacing.

I meant the exterior leak in the picture. BMW has been using magnesium valve covers on some cars since at least the early 90s — M50 and M60 motors—
and the paint or coating on the inside does flake off. The flaking has not killed those motors but maybe the earlier motors were more durable.

Not sure what a flake does when it drops? Disintegrate? Get trapped in the pick up or filter? Score a cam or crank journal?

[Mvy]

Originally Posted by pbonsalb

Not sure what a flake does when it drops? Disintegrate? Get trapped in the pick up or filter? Score a cam or crank journal?

I think the general consensus is it gets caught in the oil filter without causing damage.

[SoManyBlueCars]

Mine does it marginally, more so if the car is driven harder. I've always just wiped it off and it's been ok.

[motion732]

Originally Posted by SoManyBlueCars

Mine does it marginally, more so if the car is driven harder. I've always just wiped it off and it's been ok.

Exactly what I've been doing and ditto with hard driving. Hoping no issues. Can anyone advise?

[deansbimmer]

Crankcase pressures are higher during high rpm/wot conditions as more combustion pressure leaks past the rings than during light operation. It's to be expected that there will be more oil consumption during those conditions, plus leaks if the seals are not 100%.

[motion732]

Originally Posted by deansbimmer

Crankcase pressures are higher during high rpm/wot conditions as more combustion pressure leaks past the rings than during light operation. It's to be expected that there will be more oil consumption during those conditions, plus leaks if the seals are not 100%.

Thanks for the response.

It seems like one impact would be a slight loss in power (material?). Any other detriments, other than oil in engine bay?

[deansbimmer]

Your butt dyno wouldn't be able to notice any difference in power at this level. Oily engine bays deteriorate plastic and rubber parts faster. It seems oily-leaky valve covers also bubble up their coating faster. There may not be an immediately noticeable detriment but it will cost you in the long run.

[svinfinity]

I have some seeping through a couple screws but that seems to be the extent of it. I don’t notice any oil loss.

[motion732]

Originally Posted by deansbimmer

Your butt dyno wouldn't be able to notice any difference in power at this level. Oily engine bays deteriorate plastic and rubber parts faster. It seems oily-leaky valve covers also bubble up their coating faster. There may not be an immediately noticeable detriment but it will cost you in the long run.

Thank you. I clean it off whenever it becomes noticeable as I keep my engine bay as clean as I can. Hopefully no other ill effects.

I wouldn't even call it a leak, more of a slow 'sweat'. Every 3 months or so I'll clean it off.

[delirium330]

Just got a quote from a reputable indy shop for this job:

$760 for gaskets.
$900 for gaskets and both oil separators (no additional labor for this, just parts).

I was debating to DIY this... any opinions on length of time/difficulty to DIY? I think I'll plan to do the oil separators either way. I did DIY my E46 ZHP valve cover gasket in the past and have DIY'd my spark plugs on the e92, so that is about as close as I've gotten to the e92 gaskets.

If I DIY, looks like roughly $100 in gasket parts (2 x 11127838271/2) and $200 in oil separator parts (2 x 11157848155), so roughly $300 in parts to DIY. End Result = $600 for shop to do this.

Also, FCP Euro sells a valve cover gasket kit for $176 that includes 8 spark plug tubes... do those need to be replaced as well?

[M3MPH1S]

Originally Posted by delirium330

Just got a quote from a reputable indy shop for this job:

$760 for gaskets.
$900 for gaskets and both oil separators (no additional labor for this, just parts).

I was debating to DIY this... any opinions on length of time/difficulty to DIY? I think I'll plan to do the oil separators either way. I did DIY my E46 ZHP valve cover gasket in the past and have DIY'd my spark plugs on the e92, so that is about as close as I've gotten to the e92 gaskets.

If I DIY, looks like roughly $100 in gasket parts (2 x 11127838271/2) and $200 in oil separator parts (2 x 11157848155), so roughly $300 in parts to DIY. End Result = $600 for shop to do this.

Also, FCP Euro sells a valve cover gasket kit for $176 that includes 8 spark plug tubes... do those need to be replaced as well?

Definitely do spark plug tubes. I had a spark plug tube leak that prompted me to do the valve cover gasket job, so change them now while you're in there. Depending on how many miles/years are on your car it is a good idea to replace the o-rings around the bolts for the valve covers. The only problem is...for the S65 they decided they wouldn't sell the o-rings by themselves...you have to buy the bolts together. This ended up being the most expensive part of the repair. But since I was at 113k miles it made sense to go ahead and change them.

It's not that difficult of a job to DIY. Getting the plenum off can be a little tricky if you've never done it, and getting the clips off the fuel rail is kind of aggravating (a tiny pick/hook tool was extremely helpful here). I had been under the plenum before, but never done a valve cover gasket job and it only took me about 3 hours.