advice with N54 Mystery turboleak

[MrBlonde]

Hi all

I have a 2007 335i N54 with a problem, a leaking front turboseal.

its strange because I have changed the turbos twice and the front turbo starts leaking front the seal right away.
what could cause this?

I have done a leakdown test ,a compression test , smoke test, checked oil return hoses,looked inside engine at oil return ,turbo shaft play, oil thickness ,
oil level in the oilpan, have installed RB ext PCV with blocked headports,

there is no smoking

I would suspect a drain problem, but as stated have already looked into that, I was thinking maybe blowby pressue was preventing the oil from draining but leakdown was good. Also its only the front turbo, and I the drain is sitting a little lower than the rear, but Im aware of the oil level in the pan.
And wouldnt too much blowby pressure affect the rear also?

anyway I could really need some suggestions as to what I could look into

 

[boost3d]

Quite a few coolant pipes are around the area of your front turbo.... Have u checked the condition of your coolant bottle, pipes etc? If there's white residue, it's usually a sign of coolant leaking and possibly dripping onto your front turbo.

 

[MrBlonde]

Quite a few coolant pipes are around the area of your front turbo.... Have u checked the condition of your coolant bottle, pipes etc? If there's white residue, it's usually a sign of coolant leaking and possibly dripping onto your front turbo.

no coolant residue , there are no leaks besides the oil weaping from the seal.

 

[Twinz]

Just so i understand...what do you mean by "front turbo seal"

Do you have a pic of this and where its leaking? Its odd that the same problem persist since you changed the turbos twice? I assume you replaced the turbos? Or same turbos that got fixed?

 

[MrBlonde]

Just so i understand...what do you mean by "front turbo seal"

Do you have a pic of this and where its leaking? Its odd that the same problem persist since you changed the turbos twice? I assume you replaced the turbos? Or same turbos that got fixed?

its where the chra and exhausthouse join up.. if you know the N54 setup