[mrexcuse]

123k kms on a 2016 X1 28i.

for the last 5 to 10k i have been picking up a sour smell from the rear of the vehicle - most likely from the exhausts. I can smell it in the parking garage and when I am following the vehicle.

Has anyone run into this? Thinking it is something to do with the cat or something else in the emissions system.

Trying to get some idea of what it could be before heading to the dealer - no error codes come up on the dash.

Thank you!

[lonegun]

Originally Posted by mrexcuse

123k kms on a 2016 X1 28i.

for the last 5 to 10k i have been picking up a sour smell from the rear of the vehicle - most likely from the exhausts. I can smell it in the parking garage and when I am following the vehicle.

Has anyone run into this? Thinking it is something to do with the cat or something else in the emissions system.

Trying to get some idea of what it could be before heading to the dealer - no error codes come up on the dash.

Thank you!

Sounds like your catalytic converter might be damaged. That sour smell is probably from the sulfur. Or perhaps there's a leak before the cat. If the exhaust temp is not high enough, the cat won't work correctly either. Better check the exhaust temp with a OBD2 scanner.

Better go get it checked out at a mechanic.

[Peter_R]

Originally Posted by lonegun

Sounds like your catalytic converter might be damaged. That sour smell is probably from the sulfur. Or perhaps there's a leak before the cat. If the exhaust temp is not high enough, the cat won't work correctly either. Better check the exhaust temp with a OBD2 scanner.

Better go get it checked out at a mechanic.

Agreed.

[mrexcuse]

Sounds good,

Thanks for the confirmation. I'll schedule an appointment to get it looked at.

[mrexcuse]

Update:

Took a look at connections - nothing seems to be loose. Can't get into a dealer until June 21. I'll monitor a bit closer but it isn't a consistent smell.

So far:
1. No smell after cold start up
2. Smell comes up a few minutes after startup
3. Short drive smell is still there, but to a lesser degree.

Next on my list is a longer drive that I will monitor and see if it is still there - seems to be very sporadic. If the CAT was the issue would it be this sporadic?

[Skyline2.0]

Could it be your cabin air filter? I used to get a funky sour smell right on start up, which went away after a few minutes. It was caused by mold/bacteria on the cabin air filter/AC evaporator. The smell has been gone since using a cleaning product on the evaporator and replacing the air filters last summer.

[Peter_R]

Originally Posted by Skyline2.0

Could it be your cabin air filter? I used to get a funky sour smell right on start up, which went away after a few minutes. It was caused by mold/bacteria on the cabin air filter/AC evaporator. The smell has been gone since using a cleaning product on the evaporator and replacing the air filters last summer.

Agreed. The most likely cause. As previously stated, best to speak to dealer/mechanic. Perhaps change it yourself?

[mrexcuse]

No, this smell is coming from the exhaust, not from the inside of the cabin. I am familiar with the A/C smell and since i purchased the vehicle i tend to shut off A/C when i am 5 minutes from home to dry out the system as well as I can to avoid this. Has worked pretty well on the vehicle to avoid the smell.

It has been hit or miss this last weekend with the sour smell so I am probably going to cancel the appointment with BMW to avoid paying a diagnostic fee that may/may not give me results.

Appreciate the help on it.