Oil on rear diffuser

  • Hi,

    I have a X-BOW RR. Last week I was changing the motor oil and noticed an oil stain on the inside of the rear diffuser near the right rear wheel. When I looked up, part of the steel chasis above the stain was also covered in oil and it all seems to come from a line feeding into the turbo. Now the car is in my garage without the rear diffuser installed and a couple oil drops emerged on the garage floor. Is it normal or more likely there is a problem with the turbo? In one youtube video about motor oil change in X-BOW there was the same oil stain as I have so perhaps this small leak is normal? I drove the car after the oil change and it drove great..still feels crazy fast :))

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  • Change the line and add new copper rings! Dont the risk, that the oil supply line burst and the engine catch fire, when oil mist/spill goes to the glowing exhaust manifold!

  • Thanks guys. I’ll check the line. You’re right that hot oil spilling onto hot catalytic converter is a bad combo :).

    Is it easy to detect a leak from the line vs a leak from the turbo? My X-BOW service is far from home so I need to diagnose it myself if possible..

  • Habe versucht, die Schrauben an den Leitungen 9 und 20 festzuziehen. Es war nicht möglich, alle festzuziehen (sehr dünne und lange Schraubenschlüsselverlängerung wäre bei Leitung 20 erforderlich und Demontage vieler Teile bei Leitung 9) und die anderen fühlten sich nicht locker an, Ich habe vielleicht eine 1/10 oder 1/8 Drehung geschafft. Hoffentlich wird es reichen.


    Tried tightening bolts on lines 9 and 20. Wasn't possible to tighten all of them (very thin and long wrench extension would be required on line 20 and disassembly of many parts on line 9) and the other ones didn't feel loose, I managed maybe an 1/10 or 1/8 of an turn. Hopefully it'll be enough.

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  • Ich habe das Auto ein paar Mal herausgenommen, nachdem ich die empfohlenen Schrauben angezogen hatte, den Diffusor aus dem Auto gelassen und Aleluja! Keine Öltropfen mehr. Kann immer noch nicht glauben, dass es wirklich funktioniert hat. Hat mir den Gang zum Service Center erspart. Danke Leute.


    I took the car out a couple of times after tightening the recommended bolts, left the diffusor out of the car and aleluja! No more oil drops. Still can't believe that it really worked. Saved me a trip to the service center. Thanks guys.

  • So after initial excitement it started leaking oil much more than before, the whole diffuser was covered in oil. So I replaced all four washers on the turbo oil feed line (number 9 on the drawing) and I replaced both seals on the turbo oil return line (number 20 on the drawing). Then I noticed that there are 2 bolts missing on the turbo! You can see it on the attached picture. I'm baffled that someone could install a turbo with half the bolts missing on my car, well shit happens I guess. These bolts hold the turbine and compressor part together. Sourcing the bolts turned out rather difficult, because Audi/VW dealer can't order them, because they can order only the whole turbo and they can't even see what parts it's made of - the policy is changing one turbo with another and never repairing them at the dealer/service. Luckily I managed to get them from a local turbo shop, but only because they happened to have some leftover ones. Unfortunately it's not possible to re-install both of the bolts with the turbo mounted on the engine, only one can be reinstalled - I don't have tools to take out the whole turbo so the last bolt is still not attached.

    Took the car for a test drive, drives fine but it still leaks oil. The source of the leak seems to be the necklace because that's where the oil drops form - see the picture. What do you guys think? Do you think it's leaking because of the last missing bolt or because of some inner seal that's worn? What would you do?