My 2004 S80 turbo is leaking oil. I have followed the leak and found oil coming from the air box under the intake is being pulled up through a hose all the way to the intake and leaking out the turbo hose. I was wondering how involved this repair is and what parts I need to get from volvo.

Interesting discovery.

The oil separator box is attached to the block above the oil line and is designed to pull vapor from the crankcase. The box itself is designed to cool the vapor and allow the oil to run back into the block. Obviously, some vaporized oil will make its way to the intake just before the turbo.

Most cases, with oil in the intercooler pipe, are the result of the turbo seal leaking oil and allowing the oil to enter the IC piping. This oil is only pushed through the turbo while the turbo is in boost mode.

i hear what u are saying. the first thing i did was change the turbo because the leak mimics that. i am a mechanic myself and i spent 250 dollars on a shotgun diagnosis. i really thought it was the turbo. after replacing it, same issue. i have run all the lines that could possibly leak oil and i am 99 percent sure that the vaccuum is pulling the oil up from the box and into the intake. my cat is on its way out now probly because oil is going through on a constant basis. i am on here seeking answers because my next repair is going to be the box and all hoses attatched to it. not a easy or inexpensive quest. but im almost positive this is it. after this im stumped. dont want to take up ur time but would u like me to take video of this maybe u can get a better view.???


...appreciate ur time and help

Keith Jackson

R&Ring the oil separator box is easier than R&Ring the turbo. Figure about 5 hours to remove the manifold and replace all of the lines. The only way that oil can get 'sucked' up the breather line is for the drain port to the block to be clogged completely up - something I have never seen if synthetic oil has been used.

It has been suggested to put the front of the car on ramps to lessen the need to constantly bend over the engine bay. All nuts and bolts can be accessed from the top, crawling under the car is only needed when dropping things.

the drain port to the block?? can that be cleaned or replaced if clogged??

Yes, it looks like calcified sand. Just ream it out. You can probably soak and clean the breather box, but the vacuum lines tend to get brittle with age and probably should get replaced.

I would check the vacuum system before you order any parts. Just place a latex glove over the oil filler hole, engine warm, and start the engine. If the glove starts to get pulled in, the breather is working.