fusionchicken

Hello all, 2008 535i here with the N54 engine

So after tracking down where my engine is leaking oil (it's leaving nice puddles of oil on the garage floor and my oil level is dropping steadily) I found where one of the oil cooler hoses connects to the oil cooler to be dripping oil, and the fan blows the oil onto the serpentine belt and pulleys, both of which I just replaced last month at a shop. Lovely. Here's a video of the leak in progress with the engine idling https://streamable.com/s/uxskz/yyyimb

I took out the oil cooler today and inspected where the leak is coming from, but I can't tell why or how there would be an oil leak. I've included 4 angles of where I saw the oil leaked from the oil cooler in the pictures below. The oil cooler hoses are both brand new from BMW and were professionally put in by the shop last month, with new orings

A helpful user suggested maybe I can try high temp JB welding any cracks I see on the oil cooler but I don't see any?

Where the oil cooler hose connects to the oil cooler, the oring is allegedly brand new from the shop that worked on replacing my oil cooler hoses last month, and the oring looks fine to me? I'll replace the orings for both cooler hoses anyways but I am trying to fix all the leaks before I put everything back together. Maybe the orings were the wrong size??

Is there a way to test the oil cooler to see where it's leaking from?

ripley

If possible clean it, close one end, add some air pressure from the other end and either submerge in water or spray with soapy water around suspect places (connection points).

fusionchicken

Thank you sir, is it safe to get water into the oil cooler? I just purchased new orings will try cleaning all connections and putting on new orings first, I really don't see how the oil cooler itself could be leaking. Maybe I'll just JB weld everything together so I at least know for sure there won't be any more leaks lol

audiophool

JB Weld wouldn't stop leaks. My money is on the o ring. Make sure to lube it before assembly so it doesn't pinch.

fusionchicken

Ramos713

Where you able to fix the problem I can’t seem to figure it out the o ring looks fine on mine as well. Any help would be appreciated thanks!

Gagandeep Singh Gill

did you solve it

Gagandeep Singh Gill

what was it

08535

Only looking at pictures and not the actual cooler/lines up close it's hard to judge. But it's possible that you have a fissure in the cooler where the oring should seal. Try to magnify that area and look closely, Unfortunately it be almost impossible to see but opens up under pressure. Good luck my friend

pavjayt

Hello Guys,

My leak is driving me nuts. I am sure that it leaks from the hoses connection to the filter cooler housing and/or the thermostat. Replaced all 3 o-rings (2 for the hoses and 1 for the thermostat) and still leaks after a short drive (as soon as the thermostat opens up). The hose connections to the oil cooling radiator itself are very clean and no leaks at all. I am running out of ideas. Any suggestions are very much appreciated before shelling out hundreds on the hoses and cooler housing.

thanks