Smoking from exhaust

[Beamerboy]

Hello, First time poster here.

I have a 2021 3.0 and recently it started coughing smoke from the exhaust after catless dp install. I tried searching through the forums and found some similar threads but figured I’d try my own. It’s mainly noticeable in stop and go traffic when decelerating. It doesn’t smell like coolant so I imagine it’s oil. Under throttle there’s no smoke or If I just sit and idle there’s no smoke. Catless downpipe shouldn’t cause this right?

I guess my question is where should I start to find the issue. Start with a catch can and see if it goes away? Or put stock cat back on and take to dealer.

Thanks

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[skyviper80]

I took mine in for an oil change at a dealership and it started to smoke as you described. After about a month of searching forums I took it to a BMW mechanic who did an oil change. Problem has been gone since.

 

[Beamerboy]

I took mine in for an oil change at a dealership and it started to smoke as you described. After about a month of searching forums I took it to a BMW mechanic who did an oil change. Problem has been gone since.

I’ve had two oil changes since the smoke started happening so i don’t think that’s my issue. Maybe going to 5w30 or 40 would help

 

[Decimari]

I dealt with the same thing, it was resolved by using less oil to fill up in the oil changes. It wouldnt tell me if it was over filled so I drained enough to bring the green bar to the middle. No more smoking since then.

 

[Timmy_Jones]

Drive the car for a bit, make sure its fully warm. Then check the oil level through the in car menu. Might be overfilled?

 

[FuzzyRev]

Stock turbo? Any other modifications?

Got a picture or video of said smoke?

 

[Beamerboy]

Drive the car for a bit, make sure its fully warm. Then check the oil level through the in car menu. Might be overfilled?

Smoke still present after hour long drives. And that’s another one of my issues it won’t measure oil past 20%?

 

[Beamerboy]

Stock turbo? Any other modifications?

Got a picture or video of said smoke?

Stock turbo 40k miles. Catless dp,awe intake, hks exhaust and jb4. I’ll try and get a video now

 

[Beamerboy]

Stock turbo? Any other modifications?

Got a picture or video of said smoke?

 

[tharris4995]

Smoke still present after hour long drives. And that’s another one of my issues it won’t measure oil past 20%?

From what I’ve read and come to understand from the forums is that if you cannot get the car to read your oil level, then you may have a bad oil pump. (Which I guess is a common issue) I’d swap the cat back on and let the dealer handle it.

 

[Thraxbert]

From what I’ve read and come to understand from the forums is that if you cannot get the car to read your oil level, then you may have a bad oil pump. (Which I guess is a common issue) I’d swap the cat back on and let the dealer handle it.

This is my theory also.

 

[Loco38SUP]

Smoke still present after hour long drives. And that’s another one of my issues it won’t measure oil past 20%?

If you can’t measure the oil its likely overfilled. I would put stock cat back on and start a warranty claim for the oil pump and or oil level sensor.

-RJM

 

[lucky phil]

Smoke still present after hour long drives. And that’s another one of my issues it won’t measure oil past 20%?

First thing I would do is dump the oil and see how much is in there and see if it's overfilled. It only costs time. If it's not then as others have said it looks like oil pump time.

Phil

 

[Beamerboy]

Just a little update.
Put stock cat on and removed jb4. Took vehicle into dealer for unable to measure oil complaint. Tech found high oil pressure code and verified the oil level doesn’t read. They first recommended oil change which I agreed to because it was my first time at this dealer and they didn’t have any service records. Tech said high oil pressure code not present anymore but oil measurement still failing at 18%. Recommend oil level sensor which is not covered under power train warranty and wanted to charge $1500 to replace and continue testing. Told them I have a vehicle service contract so now I’m waiting for Monday so they can call the claim in and see if it’s approved.

 

[SupraYYJ]

Recommend oil level sensor which is not covered under power train warranty and wanted to charge $1500 to replace and continue testing.

Based on numerous posts here, the problem is likely the oil pump, which is explicitly covered under the 60 month, 60,000 mile powertrain warranty.

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