M57 Oil Leak: Crankcase Breather?

M57 Oil Leak: Crankcase Breather?

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Discussion

CJM36

Original Poster:

205 posts

59 months

Tuesday 13th June 2023
quotequote all
Hi folks,

Seeking advice.

Long story short, my 2006 E91 330D had an oil leak, suspected turbo so replaced. It remains to leak from the new turbo, similar spot. Garage (not specialist) says replace turbo again under warranty, but I’m not convinced. If the crankcase breather is gunked up, could this cause a leak at the turbo?

I have no history of this being done to car for reference.

d_a_n1979

9,681 posts

79 months

Tuesday 13th June 2023
quotequote all
It could be

The E65 730D Sport I had for a short while kept having oil leaks; turned out the crankcase breather was clogged and it forced the rocker gasket to split too...

Worth starting there and having a look etc

nomis36

429 posts

171 months

Wednesday 14th June 2023
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Definitely worth taking the top off the ccv. There isn’t a filter in there like there was on earlier m57s, I think it’s the vortex type which could get blocked. It’s very easy to get to so worth having a look and clean it out if required.

nomis36

429 posts

171 months

Wednesday 14th June 2023
quotequote all
Definitely worth taking the top off the ccv. There isn’t a filter in there like there was on earlier m57s, I think it’s the vortex type which could get blocked. It’s very easy to get to so worth having a look and clean it out if required.

rottenegg

811 posts

70 months

Friday 16th June 2023
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Pop off the turbo intake pipe and see how much oil is hanging around in the turbo housing. A teaspoon's worth is normal, but if you remove the pipe and oil pours out of it, that's a bad sign. Could be PCV at best, or excessive piston ring blow by at worst.

If you're running the nasty Shell Helix Ultra 0W30 stuff dealers throw in, try switching to an LL-04 approved 5W40 as it won't evaporate as much.