2012 x1 28i cold rough idle

[x1GTA]

I have a 2012 x1 28i with 32000km.
Runs perfect when warmed up.

With the recent cold weather (~32F,0C) the engine is running very rough at startup, sometimes stalling, if put in gear. I have to way about 30s for things to warm up a bit, then everything is fine.

Subsequent startups during the day are fine, since engine is warmed up.

Any ideas?

[Njerts]

Does it idle at +- 1200 rpm for about 30 sec on cold start?

[x1GTA]

Originally Posted by Njerts

Does it idle at +- 1200 rpm for about 30 sec on cold start?

Yes - as long as it's not in gear. On some of the colder morning's, it will stumble a bit, trying to idle at 1200-ish rpm.

[Njerts]

Any codes?

[kiloTHREE]

Sounds like a vacuum leak.
Also, anyone know if the n20 has tumbler flaps for cold start mix?

[x1GTA]

Originally Posted by kiloTHREE

Sounds like a vacuum leak.
Also, anyone know if the n20 has tumbler flaps for cold start mix?

I was thinking that... However my understanding of the N20 is that there is no traditional vacuum, as the intake valves control the flow directly. (The butterfly in the throttle body is held open in normal conditions).

[Alfisti]

No idea if this is an issue but with some motors from other marques the Intake valves have an issue that means they need replacing.

[x1GTA]

After reading on a lot, I'm inclined to think in this may be bad fuel injector(s).

I think I'll wait until a code is actually stored, and then take it to get inspected.

[tsusanto]

Hi, first-timer posting here, I know this post is a bit old.
But I have the same issue with my N46B20 engine, just wondering if anyone found out what caused the issue.