Random puff of smoke out of N54? Hard to track down.

IQraceworks

Specialist
Jul 7, 2020
77
25
0
Missouri
Ride
07' BMW 335i
Ever since I've had my 07' 335i (N54) I've noticed that at random times....I will get a puff of smoke out of the exhaust that smells like oil. It might do it twice a day, or it might do it twice a month..very random.

It only does it at cruising speed under no load, or at an idle. Acceleration, deceleration....no issues. Runs like a champ, no codes, no issues. I installed one of the RB PCV valves thinking that might help...nope. New flapper valve on the PCV system....no change.

Could it just be oil building up in the PCV system, and then randomly dumping it into the intake? Should my next step be to install a catch can?

I'm pretty sure it's not turbo seals.......it's too random.

Ideas?
 

Tedbuildiy

Corporal
Jan 9, 2020
209
40
0
Ride
335i
Ever since I've had my 07' 335i (N54) I've noticed that at random times....I will get a puff of smoke out of the exhaust that smells like oil. It might do it twice a day, or it might do it twice a month..very random.

It only does it at cruising speed under no load, or at an idle. Acceleration, deceleration....no issues. Runs like a champ, no codes, no issues. I installed one of the RB PCV valves thinking that might help...nope. New flapper valve on the PCV system....no change.

Could it just be oil building up in the PCV system, and then randomly dumping it into the intake? Should my next step be to install a catch can?

I'm pretty sure it's not turbo seals.......it's too random.

Ideas?
You know what, this is weird right.

But, I actually had a similar problem. I’m not saying yours is the same as mine.

But my motor never smoked, but sometimes would randomly just puff.

This actually stopped happening when I put new 17T on. So I believe something was up with the original snails.

I know it’s not much help. But maybe if you have old stockers...
 

NoGuru

Lieutenant
Jan 9, 2018
962
404
0
Just North of Detroit
Ride
BMW 335is
I don't think there is any issue if you have random puffs, well, more that the design of the motor and PCV makes it no surprise to me.

But I do think a catch can should help a bit. More so if you are hard on the motor.
 

TampaN54

Lurker
Mar 29, 2021
15
1
0
I just fixed the same issue. Replaced my valve cover. The ccv passages inside the valve cover are very small and clog easily. Valve cover is a maintenance item that needs to be replaced. Seems most don't last 100,000 miles.
 

TampaN54

Lurker
Mar 29, 2021
15
1
0
Just to add. Mine would blow a cloud of smoke randomly when at a stoplight. Seemed to happen more coming to a stop under light or no throttle. There was no real pattern to it. It's a common issue. There are several threads on many sites with the same issue solved by new valve covers. It's definitely not just me.