[GTwice]

Hi, I'm having problems with turbos on my 335is. Car is at around 100k mileage, sweet spot for issues. It appears one of the turbochargers is leaking oil, which goes on the cat, gearbox etc. So I get a lot of oil consumption, as well as hot oil smell in the cabin when stopped at the lights.

I know the proper way to do it is to get the turbochargers rebuilt/replaced, but if I'm doing that I might as well upgrade them. However, I was planning to start upgrades a little bit later, so I'm wondering if there is any quick fix, at least to stop the oil going onto the exhaust?

Also, if I do the upgrade, with an otherwise completely stock engine, do I need to do any remap/reflash/JB4? Or can I just run them without any issues, and just waste the new potential for a while?

[iqraceworks]

Have you got up under the car to see where the oil is actually coming from? Could it be coming from one of the inlet pipes that is just lose?

[Wolf 335]

Valve cover gasket is leaking and dripping on your cats.

[GTwice]

Thanks for suggestions, car was at some other maintenance and I was advised that there was oil leaking, but I guess they didn't/couldn't locate it exactly. I'm having a VANOS actuator replaced soon so that will fix the valve cover gasket if that's the case, I will also ask them to look precisely for the oil leak. Is it possible to replace all the turbocharger oil lines without removing them (I mean turbochargers)? That would save me a lot of money, as I can't DIY on it until spring.

[TheMidnightNarwhal]

Originally Posted by GTwice

Thanks for suggestions, car was at some other maintenance and I was advised that there was oil leaking, but I guess they didn't/couldn't locate it exactly. I'm having a VANOS actuator replaced soon so that will fix the valve cover gasket if that's the case, I will also ask them to look precisely for the oil leak. Is it possible to replace all the turbocharger oil lines without removing them (I mean turbochargers)? That would save me a lot of money, as I can't DIY on it until spring.

VANOS solenoids don't need the valve cover taken off to replace.

[GTwice]

Originally Posted by TheMidnightNarwhal

VANOS solenoids don't need the valve cover taken off to replace.

...

[mweisdorfer]

Use a telescopic mirror with an LED light and place it behind the valve cover near the firewall & tell us what you see. This area is the most common area for the valve cover to leak on an N54.

Also, change out your PCV valve & purge valve/ hose. If the valve on this hose is stuck, it will force excessive pressure on the the entire system and cause leaks in the valve cover & rear main seal for starters.

[mweisdorfer]

Originally Posted by GTwice

Thanks for suggestions, car was at some other maintenance and I was advised that there was oil leaking, but I guess they didn't/couldn't locate it exactly. I'm having a VANOS actuator replaced soon so that will fix the valve cover gasket if that's the case, I will also ask them to look precisely for the oil leak. Is it possible to replace all the turbocharger oil lines without removing them (I mean turbochargers)? That would save me a lot of money, as I can't DIY on it until spring.

The oil lines aren't prone to leaking on the N54. Especially at 100,000 miles. I have 171,000 miles on my original turbos and no leaks from these lines what so ever.

The leak is from above.