X5M Tune Causing Exhaust Smoke?

[xJonRx]

I recently installed catless downpipes and a tune on my X5M. After about a day or two running the setup, my car began to smoke excessively from the tailpipes. At first it was constant from the second you turned her on. I replaced the PCV hoses coming off the manifold attaching to the turbos and that seemed to immediately fix my problem. Two days later and I noticed when in M Mode and manually shifting, the car was again smoking from the tailpipes. When in boring mode the car does not smoke. Could my tune be causing this? I had the tuner option in exhaust burble, and have read a bit about the excess fuel causing smoke. Just wanted to hear some thought from you all before I head down the rabbit hole of reversing the tune, and replacing everything under the sun such as turbo seals, turbos, injectors, and lastly valve stem seals. Just seems a bit suspect since I had smoke at all before removing the cats and installing the tune.

Thank you in advance!

[Sophisticated Redneck]

Originally Posted by xJonRx

I recently installed catless downpipes and a tune on my X5M. After about a day or two running the setup, my car began to smoke excessively from the tailpipes. At first it was constant from the second you turned her on. I replaced the PCV hoses coming off the manifold attaching to the turbos and that seemed to immediately fix my problem. Two days later and I noticed when in M Mode and manually shifting, the car was again smoking from the tailpipes. When in boring mode the car does not smoke. Could my tune be causing this? I had the tuner option in exhaust burble, and have read a bit about the excess fuel causing smoke. Just wanted to hear some thought from you all before I head down the rabbit hole of reversing the tune, and replacing everything under the sun such as turbo seals, turbos, injectors, and lastly valve stem seals. Just seems a bit suspect since I had smoke at all before removing the cats and installing the tune.

Thank you in advance!

I noticed the same when I installed downpipes. I increased the crankcase vacuum and bought some time but at around 138k miles I was forced to do the valve stem seals as was smoking non-stop and oil usage was about 2 liters ever 1000 miles or so. After valve stem seals the usage dropped to less then a liter every 5000 mile oil change. I highly suspect its your seals unless you have less then 60k miles on it. Couple of things to check:

What tune are you using?

Does it release a massive amount of smoke when accelerating from a stop after sitting at a light under normal acceleration?

Grab a elm32 ob2 scanner and app like torque to monitor your air/fuel ratio on both banks to determine if its running so rich its smoking.

How much oil are you burning? If you are using more then a liter every 700 miles, your valve stem seals.

Crankcase vacuum. Drill and tap your oil filler cap or split one of the valve cover lines and install adapter for a 1/8npt fitting for a pressure gauge. Factory BMW CC vacuum is about -1 psi at idle, underboost CC should be between 0 and 1 psi.

Turbo oil return lines: More of an issue on the 50i then M as 50i is tuned to run hotter but these are known to coke up on the M too. You will burn an excessive amount of oil (liter every 200 miles or less) depending on how plugged up they are.

[xJonRx]

Originally Posted by Sophisticated Redneck

What tune are you using?

- I’m have an RK Tune running. There weren’t any reviews on our platform, but he seems like a knowledgeable tuner and it was decently priced so I went for it.

Does it release a massive amount of smoke when accelerating from a stop after sitting at a light under normal acceleration?

- It really only smokes after I have been downshifting causing the exhaust to “burble” and “crackle”. It will smoke at idle, and any acceleration. If I drive in auto there is no smoke.

Grab a elm32 ob2 scanner and app like torque to monitor your air/fuel ratio on both banks to determine if its running so rich its smoking.

-Will do!

How much oil are you burning? If you are using more then a liter every 700 miles, your valve stem seals.

- I’m actually not burning an excess of oil, but an abnormal amount of fuel. I know our cars aren’t fuel efficient whatsoever, a quarter tank lasts 35 miles on this tune.

Turbo oil return lines: More of an issue on the 50i then M as 50i is tuned to run hotter but these are known to coke up on the M too. You will burn an excessive amount of oil (liter every 200 miles or less) depending on how plugged up they are.

- I will be tackling these this week and will deport back!

I appreciate your feedback, tips, and experience!
-J

[Sophisticated Redneck]

Originally Posted by xJonRx

I appreciate your feedback, tips, and experience!
-J

np, hopefully it helps =)