Oil leak burning off of down pipe / cat, trouble locating source

[BrodieTS]

'08 with 60k miles. Car started smelling of burning oil with visible smoke coming from the engine right when I hit 60k miles (curious timing). I thought it might be the turbos which are original to this N54 however after diving in, that doesn't appear to be the case.

I visually inspected the turbos from the top and bottom of the car and could not find any oil. No sign of blue smoke or other turbo specific symptoms.
What I did find though (first pic) was oil on the bottom of the rear turbo coolant return. Pic is looking from the bottom up

It would seem to make sense that there is oil coming from above the coolant return however the pic below seems to indicate that may not be the case as there is no visible oil. Next pic now looking from the top down.

In the next pic, you can see where the oil is dripping from above onto the down pipe where it seems it is burning.

In the final pic, I also found oil dripping from what I believe is a power steering line, sourced from near the water pump electrical connection. Different section of the car but a leak nonetheless.

Before I dive into replacing the valve cover gasket I was curious if anyone else has seen something similar and was able to identify the source of the leak.

[wheela]

Not to say it is for sure your valve cover, but I had the exact same symptoms (slight visible smoking from the hood and burning oil smell when pulling into the garage) - both times it was oil dripping on the DP from a leaky valve cover (i'm n55 though).

[tracer bullet]

Agreed probably VC, it's sort of always the VC. You'd have to basically remove the plastic covers, clean everything as well as possible (spray cleaner, gentle water rinse), and then watch really closely.

Oil has a way of running along things in a super thin layer and being hard to detect (when it's not in an area that gets a ton of dirt exposure anyhow).

[BrodieTS]

Thanks for the feedback on this. Might as well start with the VC gasket anyway. The car is 15 years old and probably needs it by this point. I’ll post back a status once I wrap it up.

[tracer bullet]

Unfortunately that's probably the best thing, given that it's so likely to be it. But no guarantees of course. You might still consider taking the plastic covers off and getting a little ways into it just to be sure. It still could be something else in that neighborhood.

Stating the obvious consider the plugs and / or coil packs while you are there. Plugs for sure, since they're so cheap. Coils are probably good if you aren't detecting any stumbling / misfiring. I don't advocating replacing things that work but - be ready for anything.

[Bordi35i]

One more tip, once you have changed your VC gasket, think about cleaning the turbo head racks. It's the metallic rack that holds the turbo solenoids.

After months or even years of VC leakings, it can be full of oil. When heating, the oil residues can continue dripping on the turbo/DP and create smoke.

Think about cleaning around this area. Access is easy when rack is removed.

I attach a few pictures of the rack + turbo head, 2 months after changing my VG

Having it cleaned can help you diagnose if VG begins to leak again

[BrodieTS]

Thanks for all the help. I completed the gasket replacement yet seem to still have a pretty prominent leak. You can see oil dripping off of the exhaust bolt. Still not sure of the actual source. I'm going to replace the PCV Valve which probably should have been done as part of the gasket change anyway.

Bordi35i, good call on that head rack and thanks for the pics. Mine is definitely a bit dirty. I cleaned part of it up when I had the valve over off but probably should have done all of it. Adding that to the list.

[ShocknAwe]

Turbo oil drain or feed line probably the rear specifically.

[BrodieTS]

Originally Posted by ShocknAwe

Turbo oil drain or feed line probably the rear specifically.

I did visually inspect the oil feed lines and such around the turbos and didn’t see anything other than oil on the coolant return line which was odd (pic at the top of the thread). I assumed it had to coming from somewhere above that which led to the valve cover gasket. I’m going to get back under there though with a borescope and see what else I might be able to turn up.

[BrodieTS]

FIXED

Forgot to update the post sooner but the issue is now resolved. Seems as though it was the valve gasket as most people had suggested replacing. It just took a bit of time to burn off the residual oil that had accumulated around the engine and down pipe. Thanks for everyone's guidance in getting this squared away.