[capt_slow]

Was poking around the engine bay last month and found an oily patch on the passenger-side intercooler air duct, right where it meets the turbo. I cleaned it up and kept and eye on it, now 3000 miles later the oily patch is back.



I know the inside of that pipe can be lined with oil from blow-by, but does it look like an o-ring failed in the duct?

Planning to have the dealer look at this at the same time as the HPFP recall is done. Hopefully it's covered by the CPO warranty.

[capt_slow]

Poking around the engine bay again and I found another leaky pipe, this time on the intake. As far as blow-by related leaks are concerned, this is the 3rd one. First one I posted about before, the second is my OP, and now this.





On another note, I was poking around some ISTA articles and found "Troubleshooting in the event of leakage on the exhaust turbocharger". They describe escaping blow-by oil as a possible reason of oil leaks at the turbo. In it they have a picture of a leaky hose in the exact location as my OP, captioned "Unacceptable oil leakage at the hose connection"

I know some of these seals aren't the greatest, but could I also be looking at excessive blow-by escaping from the turbo? If it is a turbo issue, it might also explain that whistling sound from a few years ago.

[capt_slow]

I took out the air filter box to get a closer look at the pressure pipe and inside the clean air pipe. The oil leaking from the duct is a bit worse than I thought and there is definitely residue on the clean air pipe. Touched the exterior of the connector fitting and glove came back wet black. I also used the endoscope to take a closer look at the cold side of the turbo and I can see oil on intake walls.

I also ran the ISTA Air-mass system test that cycles the engine from 1000 to 2500 RPM 3x, and noticed a whistling noise as the engine revs back down from 2500.

Is all this normal?

Turbo side connector of pressure pipe to intercooler


Inside of clean air pipe (from endoscope)


Cold side of turbo with oil on the walls

[Enabled]

Honestly I would first verify crankcase ventilation system, turbo shaft for play, and then all the o-rings and the integrity of the intake pipe.

[capt_slow]

Originally Posted by Enabled

Honestly I would first verify crankcase ventilation system, turbo shaft for play, and then all the o-rings and the integrity of the intake pipe.

I did most of this over the weekend.

Disconnected PCV pipe from engine: about a teaspoon of oil spilled out. There was some oily build up on the connector, but the o-ring looked fine.
Removed the clean air pipe from the engine to expose the turbo: another small bit of oil spilled out of the intake side of the turbo and onto the steering rack. The green o-ring on the turbo looked OK. Looked at the PCV pipe and blew some compressed air through it, it didnt looked blocked.

Turbo looks OK and doesnt look damaged, also no play at all.


The original location of the leak, where the intercooler pipe meets the turbo, was as dirty and oily as ever. I couldn't for the life of me remove the pipe, I could unlock the two clips, but the pipe wouldnt budge. I know there's an o-ring in there and probably another couple gallons of oil just waiting to spill on to the steering rack.

I cleaned up all the o-rings, wiped up all the oil and blow-by, and reassembled the engine. At this point, I think its time for a trip to the dealer and use that CPO warranty.

[eugene89us]

For the oil accumulation around the "intake silencer" marked with a red rectangle, mine has had some oil on it since brand new. I think somehow that section almost creates a vacuum and retrograde moves the oil from where PCV enters the intake. That has always been dirty but no dripping there, just semi-liquid oil film.

As to the oil between turbo and intercooler, I have that also. But small amounts, maybe a tablespoon every 30,000 miles. Basically, not enough to see oil level drop between 10,000 mile oil changes and it never got on the outside. The charge pipe is sealed well to turbo. But I am also certain that the oil comes exclusively from PCV valve. The only time my turbo leaked was when PCV valve stopped up via an oil catch can. Since the can got deleted and OEM restored, no more turbo seal leaks.

I would suggest working to get the lower pipe off. You're doing right thing - the ring clip pulls out and the pipe can be wiggled free. I remember it took me some work to get it off and I ended up removing the entire intake leading up to turbo to get more space for lower pipe. I believe I used two flathead screwdrivers to pull the loop from both sides, and was able to remove it reaching from the top. If you don't pull enough, either the main rectangular ear or the two triangular end pieces do not fully retract and won't let you pull it off. I almost pulled the square metal piece out of that pipe opening before it let the pipe off.

[eugene89us]

If this helps, here is how it looks. Don't mind the oil, that was the blocked PCV, a self-created condition that was corrected. After correction, mostly oil coating pipe and not much pooling amount.

[eugene89us]

And now that I look over those pics, the middle photo does show a little bit of caked grease at the bottom. Definitely not your amounts but some found its way out. I am almost certain replacing the seals and reseating the pipe will do the trick. I ended up pulling it completely out and wiping inside and out with a towel. That was at 50,100 miles, I remember that SOB started to eat oil 100 miles out of warranty. I was ready to replace turbo until I realized it was as simple as clearing PCV and problem solved - total cost $2.00 for new worm drive clamp. Lol.

[eugene89us]

And last LOL of the day: if your dealer is anything like my dealer (and most of them have crappy workforce), the will tell you that the oil accumulation is normal. As a matter of fact, mine said:

- It is normal for your wife's X5 35d to have sooty accumulation around EGR (despite my car having double miles had none of that)

- It is normal for your wife's X5 35d to consume some coolant. All BMWs do that - although mine did not require top off in 70, 000 miles. And despite clear signs of blue substance all over her engine bay.

- It is normal for diesel soot to be around the engine compartment, diesels are supposed to be dirty.

- It is okay to use gasoline oil instead of BMW diesel oil, it is all the same.

- Those cracks on your number keys are scratches, sticking AC buttons are not covered under warranty, etc etc.

What I have learned is that if you love your car, you keep it far from dealership, and you diagnose and fix your car yourself. With all the tools we have, such as ISTA, my repair is far superior to "BMW specialists". Many here have been burnt by their dealers, maybe yours is an exception, I pray it is. But I dread the idea of letting them do HPFP recall, the hell will freeze over before I bring it to them.

[Experimental]

Originally Posted by eugene89us

And last LOL of the day: if your dealer is anything like my dealer (and most of them have crappy workforce), the will tell you that the oil accumulation is normal. As a matter of fact, mine said:

- It is normal for your wife's X5 35d to have sooty accumulation around EGR (despite my car having double miles had none of that)

- It is normal for your wife's X5 35d to consume some coolant. All BMWs do that - although mine did not require top off in 70, 000 miles. And despite clear signs of blue substance all over her engine bay.

- It is normal for diesel soot to be around the engine compartment, diesels are supposed to be dirty.

- It is okay to use gasoline oil instead of BMW diesel oil, it is all the same.

- Those cracks on your number keys are scratches, sticking AC buttons are not covered under warranty, etc etc.

What I have learned is that if you love your car, you keep it far from dealership, and you diagnose and fix your car yourself. With all the tools we have, such as ISTA, my repair is far superior to "BMW specialists". Many here have been burnt by their dealers, maybe yours is an exception, I pray it is. But I dread the idea of letting them do HPFP recall, the hell will freeze over before I bring it to them.

I had the "shop foreman" at my dealership try to tell me that smelling diesel exhaust in the cabin of the vehicle is normal. It was at that moment I realized 2 things:

1 - He was completely FOS

and 2 - If I wanted the problem fixed, I would have to fix it myself. And I did.

Bottom line is I wouldn't accept soot at the connections like your photos show, but I also wouldn't be surprised if they try to wiggle out of doing anything with it under the CPO warranty.

[capt_slow]

I was finally able to pry the charge pipe off of the turbo, using two flathead screwdrivers as eugene89us recommended. Surprisingly, the pipe was nearly bone dry and zero oil spilled down to the shop towels I placed on the steering rack!




What was more surprising was how much oil accumulated at the turbo/intake area in just the span of a week/250mi of driving.




I reinspected the o-rings, cleaned and reassembled everything up.

[eugene89us]

Glad you were able to pull it apart. When my turbo seals were temporarily leaking, the oil was coming through the bottom section. My intake top pipe did not have visible oil beside the normal slickness of the surface from PCV system. If your charge pipe downstream of the turbo is bone dry, then I would postulate that your turbo seals are fine. Because their leak would be moved both by gravity and airflow downstream. So that leaves the only source of the leak to be from the PCV system. I wonder if the oil then accumulates in the puddle immediately before the turbo, finds its way out and drips onto the charge pipe, which then creates all this accumulation on the outside of it. So the question is then why would your PCV system release so much oil? I presume the engine oil level in the sump is not horribly overfilled? I don't think there is any other source of oil in the intake, besides PCV system and the turbo itself. When PCV functions properly, only a small amount of about a tablespoon is released every 6 months, most of it finds itself in the combustion chamber and only small slick layer is deposited on the piping itself. I am deferring to experts, I reached the dead end.

[capt_slow]

Now that all the parts are cleaned and pipes reseated, I'll keep an eye on it to see if the leak reoccurs. Now that I know what I'm dealing with, I know what to look out for. Agree that there is a chance the oil could be leaking from the intake just before the turbo. The part was replaced by the dealer in Jan 2020, so it's possible it wasnt seated in properly.

As for the amount of oil build up, I did mostly city driving on short distances that week. Could it be the amount of blow-by increases while the car is still warming up?

[capt_slow]

Originally Posted by eugene89us

I wonder if the oil then accumulates in the puddle immediately before the turbo, finds its way out and drips onto the charge pipe, which then creates all this accumulation on the outside of it. So the question is then why would your PCV system release so much oil?

Originally Posted by capt_slow

Agree that there is a chance the oil could be leaking from the intake just before the turbo. The part was replaced by the dealer in Jan 2020, so it's possible it wasnt seated in properly.

This is indeed the source of the leak. One week and 500 miles later, a thin film of oil has started forming at the bottom-side of the intake just before the turbo. The charge pipe directly underneath looks clean still.

[Enabled]

I'd figure that the diaphragm that does the CCV/PCV action is damaged.
You can pop off its cap and check.

[etsfreak]

I additionally changed the membrane of the crankcase and that helped for the oily turbo as well

[Watsey]

Originally Posted by etsfreak

I additionally changed the membrane of the crankcase and that helped for the oily turbo as well

Do you mean you replaced the PCV diaphragm ?

[etsfreak]

Thanks! Yes thats the right term for it - sorry -

[andreigbs]

Dumb question: where exactly is the PCV and how would I know if it needs replacing?

[Enabled]

Originally Posted by andreigbs

Dumb question: where exactly is the PCV and how would I know if it needs replacing?

There is a rubber diaphragm under this cap that helps with reducing the oil vapor back into liquid.
Normally it should just work. Rarely it can fail, which may be the case. It seems easy enough to inspect under the cap by raising the tabs gently top remove the cap.

Here it is from a random pic I had from valve cover gasket replacement.

[capt_slow]

Originally Posted by Enabled

There is a rubber diaphragm under this cap that helps with reducing the oil vapor back into liquid.
Normally it should just work. Rarely it can have failed, which may be the case. It seems easy enough to inspect under the cap by raising the tabs gently top remove the cap.

Here it is from a random pic I had from valve cover gasket replacement.

Dealer confirmed crankcase pressure out of spec and the diaphragm failed. Oil was starting to seep into the PCV heater connectors too. Getting a new valve cover and intake. Thanks for all the help! I'd like to think the leg work we all did helps give the dealer techs a head start. All work covered under CPO. Car has about 1 month left in the CPO warranty and I paid about $1600 to do the CPO when I bought out the lease. I think it paid for itself with this repair alone ($700 parts, plus dealer labor?)

Service notes:

INSPECTED AND FOUND OIL LEAKING FROM TURBO INLET PIPE,REMOVED INLET PIPE AND FOUND EXCESSIVE AMOUNT OF OIL IN THE PIPE. FOUND OIL TO BE LEAKING FROM BREATHER VALVE CONNECTOR. CHECKED HISTORY AND FOUND BREATHER HOSE HAS BEEN REPLACED. SUSPECTED OIL TO BE COMING FROM CRANK CASE, ASSEMBLED VEHICLE, LET ENGINE IDLE AND CHECKED CRANK CASE PRESSURE. FOUND 3.3MBAR (SPEC 0.0 +/- 3.0) FOUND CRANK CASE TO BE OUTSIDE OF TOLERANCE CAUSING OIL TO LEAK INTO BREATHER HOSE. CRANK CASE IS BUILT INTO THE VALVE COVER, REMOVED AND REPLACED COMPLETE VALVE COVER, REMOVED AND REPLACED BREATHER HOSE DUE TO COLLATERAL DAMAGE. ASSEMBLED VEHICLE, CHECKED CRANK CASE PRESSURE A SECOND TIME AND FOUND 0.8MBAR. TEST DROVE VEHICLE AND ENGINE OPERATING NORMALLY

I think the bolded parts are a typo (misplaced decimal?) as I thought the tolerance was -15 to +30 mBar.

[capt_slow]

Welp, after 9 months and 9K miles later, I think the problem is back. I noticed faint traces of oil coming from the turbo-intercooler pipe and started looking for signs of a PCV problem again.

Oil residue leaking out of intake 9-month old intake pipe


Faint traces of oil leaking from seams of 9-month old valve cover


Consider I know what to look for this time, I tried some other things while the engine was idle (cold and warm). There was enough pressure to cause the unseated oil cap to dance around, and enough to blow a paper towel sheet around.

What are the chances the CCV broke again?