[MCCoding]

Hi all

As the title states I cannot seem to find out what this part is! And it's 1/2 of the oil leaks in my engine bay.

Despite a specialist claiming its my turbo seals I'm 95% certain its this oil pipe right here but I cannot seem to find the part number physically or on realoem

Please help

I've attached a pic below. It seems its going to/from the radiator into the engine block (not turbo and not to the gearbox)

Please see below, it's the 2nd/lower pipe

I've searched Google for 335d oil pipes and I still can't seem to find it lol

[e91Owner]

Those are your ac condenser lines. So unless is PAG oil, there is likely just engine oil on them from something else.

[MCCoding]

Originally Posted by e91Owner

Those are your ac condenser lines. So unless is PAG oil, there is likely just engine oil on them from something else.

Ahhj I think you're right. Just searched up and the lines are a match.

Back to the drawing board - why tf is my car leaking oil with no visible exit!?

From research it seems the usual culprit is the turbo pipe to the intercooler. But as you can see mine has been replaced and securely on

My other suspects are
- The intercooler leaking although it's an upgraded intercooler
- The oil feed line below the big turbo which is something even I won't bother attempting despite my mechanical curiosity

Any other culprits?

[e91Owner]

There aren't a lot of 335d owners around so unfortunately you're likely to get answers that only might apply, based on experience with other engines.

[lnxguy]

That's oil leaking out the IC hoses. Oil in the intake tract is completely normal, the lower boost hose will always drip/leak at some point.

Take a peak at the hose itself, any chance its torn?

100% not your turbo seals lol.

[Tambohamilton]

That looks like a lot of oil to be a small leak in the air intake/intercooler hoses. Don't know enough about the 35d to give a better suggestion though.

Have you tried washing it down with brake cleaner etc, wait for all the cleaner to evaporate then go for a drive. Then check to see where the oil is, as thatll give you a better idea of where it's coming from

[zellamay]

You could clean the area, then shove paper towels in suspected spots, drive it, look for an oily paper towel.