Rough idle problem

[BLM06]

Looking for some help. 2010 116i M sport with the 2.0na engine. When cold, car ticks over perfectly. After about 15 mins of driving when idling you can feel it getting a little bit rough. Nothing too bad, but the longer you idle the worse it gets. No EML. When running car runs perfectly not a flicker. Today left it idling for 10mins after I felt it and then revs started to fluctuate but still no eml. OBD scanner can’t pick anything up. Turned it off and back on and was still rough but only a little bit like when it just starts. Anyone had anything similar or can point me in a direction of where I should start looking?

[Greydog]

Morning Billy

When was the car last serviced ? The symptoms you describe could be due to an air or vacuum leak, old hoses seals and vacuum lines can start to crack when cold they are stiff and don't leak (as much) when hot and flexible you see the issue developing.

Your OBD Scanner needs to be BMW capable a standard scanner will only see critical functions.

Dave

[BLM06]

5 hours ago, Greydog said:

Morning Billy

When was the car last serviced ? The symptoms you describe could be due to an air or vacuum leak, old hoses seals and vacuum lines can start to crack when cold they are stiff and don't leak (as much) when hot and flexible you see the issue developing.

Your OBD Scanner needs to be BMW capable a standard scanner will only see critical functions.

Dave

Hello Dave thanks for your reply, 

thanks for the reply and it does sound like that could be the problem. I was thinking injector but never pops an engine light up so wasn’t certain. Was serviced 6500 miles ago but was just oil and filters. 
 

Going to check later and see if I can see any visible cracks or splits. Got a friend who has a garage and will obd and smoke test it for me.

 

Billy

[BLM06]

6 hours ago, Greydog said:

Morning Billy

When was the car last serviced ? The symptoms you describe could be due to an air or vacuum leak, old hoses seals and vacuum lines can start to crack when cold they are stiff and don't leak (as much) when hot and flexible you see the issue developing.

Your OBD Scanner needs to be BMW capable a standard scanner will only see critical functions.

Dave

Hello Dave,

Just an update and I think you may be right. Went out and gave it a few revs when cold, nothing. Let it warm up and there was a loud “shoooo”. I’ve attached a photo of where the sound was coming from. Going to get it looked into but do you have any idea of what it could be? First BMW, always had vag cars so engine are a little different to what I’m used to