Stage 2 tune: My SCR, DPF, EGR and Urea delete Journey

[Stockx5]

After 50 miles, smoke smell still persists. it's an exhaust smell and it comes on as soon as the car is turned on. If it's 30 degrees outside and if it was related to oil burning it should have taken some time for it to warm up and steam of.

instead it comes right away as the car is started. Im starting to think it's exhaust related again.

Next idea is to use a hose as a stethoscope and poke around the turbo area see if there is noise or any leaks coming from there.

other than that the only other way would be to plug in a smoke machine thru the tail pipe side and see with a camera if it leaks from the engine side.

[seattle]

Was smoke smell there before your DPF delete and new downpipes?
If yes, I'd suspect a leak there...

[Stockx5]

I cant recall the smoke smell being there before the delete. Which puzzles me.

I did bring the car twice to the muffler shop. with the car raised we made sure nothing was leaking from the new exhaust.


we did notice exhaust leaking somewhere around the turbo area. my conclusion at the time was that probably the wastegate leaks exhaust and this is normal for these cars from what I have seen.

[Stockx5]

The stethoscope did not turn out any new info other than there is a minor leak somewhere around the turbo area and it is not easy to get to.


found an old post of interest over at e90post

I had the same thing happen last year. Here are all of the parts they threw at it. In the end, they suspected the two gaskets and back pressure pipe caused the whole problem but I got a new DPF and Nox sensors out of it so I was happy. All of my work was done at Thompson BMW in Doylestown, PA if they want to call over to them.

7/17/2012

THROTTLE 1 11717804384 409.67 409.67
O-ring 1 13547792098 3.77 3.77

7/26/2012

Sensor for NOX 1 13628511666 461.38 461.38
Sensor for NOX 1 13628511665 461.38 461.38

10/19/2012

AT-Diesel particulate filter 1 18307808655 2302.56 2302.56
Gasket 1 18307793678 11.24 11.24
Clamp 1 18207793677 45.71 45.71
Gasket 1 18307812171 8.46 8.46
Hex nut wiht flange 2 18307620549 0.9 1.8
Gasket Asbestos Free 3 11627799728 11.73 35.19
Flange nut 12 11627789015 0.59 7.08
Gasket ring 2 7119963129 0.57 1.14
Gasket ring 2 7119905041 0.57 1.14
3M 08180 High Power Brake Cleaner - 14 oz. 2 8180 7.45 14.9
Antifreeze - 1 Gallon - Genuine BMW 1 82141467704 23.95 23.95
ATF Dexron III 1 ATF 12.95 12.95
Pipe, backpressure. 1 13627812806 15.31 15.31
Mixer. 1 18308512438 100.46 100.46
Collar nut 2 11627509731 2.6 5.2
Acoustic cover rear. 1 11147807246 66.9 66.9

looks like the dealer threw a lot of parts/gaskets at it to try to figure out the problem and ultimately it looks like it ended up being the manifold gasket

so now it seems plausible that the manifold gasket has a leak and needs replacement. since access to it entails removing both turbos including exhaust and right engine mount I will first do more diagnosing with a smoke machine.

If it ends up being the exhaust manifold gasket this is one rather big project.

[seattle]

There are also gaskets between exhaust manifold and each of the turbos.
#5 and #6 here.

I have my turbos removed now for rebuild. Observed one of these gaskets was burned more than the other.

Purchased new ones and they are in my garage now waiting for turbos.

Each gasket actually consists of about 4 thin plates. I can imagine with age and stress, they become compressed and burned, and thinner, thus leaking exhaust.

[seattle]

Originally Posted by Stockx5

I cant recall the smoke smell being there before the delete. Which puzzles me.

I talked to Dima (DUDMD) the other day at his shop. He did mention that after deletes, it is normal for x5d to start puffing a bit of smoke for a second on cold starts. On non-deleted, same smoke would not be considered normal.

Could that explain why you get exhaust smoke where didn't before the delete? Delete may have exposed something that was there for a while.

[Stockx5]

Originally Posted by seattle

There are also gaskets between exhaust manifold and each of the turbos.
#5 and #6 here.

There are no burn marks around those gaskets, but really who knows for sure until I remove the turbos and look.

Originally Posted by seattle

I have my turbos removed now for rebuild. Observed one of these gaskets was burned more than the other.

Purchased new ones and they are in my garage now waiting for turbos.

Each gasket actually consists of about 4 thin plates. I can imagine with age and stress, they become compressed and burned, and thinner, thus leaking exhaust.

really, how difficult is it to get everything off? I hear on other cars some people run gasketless turbos to avoid having to continuously replace the gaskets. are the surfaces smooth enough to allow that?

Originally Posted by seattle

I talked to Dima (DUDMD) the other day at his shop. He did mention that after deletes, it is normal for x5d to start puffing a bit of smoke for a second on cold starts. On non-deleted, same smoke would not be considered normal.

Could that explain why you get exhaust smoke where didn't before the delete? Delete may have exposed something that was there for a while.

That makes a lot of sense. I do feel the burning smell is less now that the ccv boot has been fixed. makes driving the car more bearable for now until it's warm out and I can tackle the turbo gaskets. if that proves to be the problem after hooking up the smoke machine.

I just don't want to remove everything and the issue turns out to be something else.

why did you remove your turbos?

[seattle]

Originally Posted by Stockx5

why did you remove your turbos?

Long story. Been observing oil in the intercooler back since it was still under warranty. At some point, intercooler rubber seal was even replaced under warranty. Of course, I never questioned why there's oil in the first place, when only clean air was to be expected. And idiot dealer was saying it is normal. Idiot me was not questioning.
Then, around 80K miles, I suspected the oil is actually from blowby. It was the case, indeed. Even had the same return hose fail because of being soaked in oil -something it was not designed for. So, took care of that by installing ProVent filter. That hose is now basically clean.

However, kept seeing oil pushed into intercooler. So, strongly suspected the turbo (either one) is leaking oil.

Took it off (used your steps of DPF removal, as removing turbo requires removal of DPF), dropped off at local Borg-Warner certified rebuild shop.
They took it apart and confirmed the larger turbo's shaft has worn and is to blame for leaking oil.

The smaller turbo is in decent shape. I suspected that too, that smaller turbo was not to blame for oil, just by tracing the pipes to see where oil originates.

Here's the problem: parts are hard to find! The shop said wait time is about 10 weeks.
Called Borg-Warner itself - though they don't sell directly, they did mention the 10-week may be cut off by paying for expedited shipping.

So, I am at this point thinking if buying a new low-pressure turbo is just going to be faster! Yes, rebuild of it will end up being about $800 when it is over, but I have seen new one for $1,200 somewhere.
If I don't end up getting it rebuild, there is a $125 disassembly fee. So, new would end up costing closer to $1,400 taxes/shipping and all.


Will talk to the shop on Monday to see if there's any updates and what my expedited shipping options are, if any.

By the way, I am getting rid of emissions (DPF, urea, EGR), but will have DOC (diesel cat). Hoping that would eliminate/reduce diesel smell when idling. Plus, I do care just a tiny bit about environment after all. But mostly smell.

[Stockx5]

oh wow what a pain, what would cause premature turbo shaft wear ? I guess it's not uncommon but this seems premature. and how much oil where you consuming?

Im sure with time parts will be more readily available as the cars age.

Do tell us how the cat works

[seattle]

Meanwhile, the lower turbo.

Stopped by the shop today and was shown where shaft was damaged on turbine side at the piston seal.

Since the shaft itself (borg warner turbo) is nowhere to find as part, and new BW turbo runs at $1,900 new, the shop is looking at fitting larger seal and match the shaft to it by machining the shaft.

That still does not explain why oil leaking from compressor side.

Or maybe it does. Since the piston seals are meant to hold gas/air from entering turbo housing (compressor or turbine side), could this widened piston ring allow exhaust gasses to enter the housing and mess with oil return, somehow forcing oil to escape through compressor side piston ring?

On the photo: notice wear/damage at on left side of the square groove.
The round groove is called "oil fling", meant to reroute oil away from piston ring. Again, the piston ring itself is meant to seal gas/air, not oil.

When oil gets there for any reason, the ring is not good at sealing it. Similar to charge air pipe seal that we all have experience with leaking oil.