Rough idle at startup.

[SM2983]

Hi all,

Wonder if you can help me please.

I have a 2009 330d E90 LCI auto (71k miles). The car has always been serviced regularly by BMW and has run well since I've owned it (2.5 years).

Over the last few weeks, on start up, the revs idle a little erratically. Then, when driving forward or in reverse, the revs continue to go slightly mad until the car has been driven for about 1/2 mile. It then goes back to normal.

This only tends to happen when the car hasn't been driven for a number of hours.

Any ideas?

Cheers.

[modular93fox]

Intake ports are most likely guaranteed to be clogged with carbon buildup. No easy cheap fix there
But faults will tell you what's going on other than an educated guess

[SM2983]

Hi there and thanks for the quick reply.

If this is the issue, is it likely to get worse as time goes by? As I say, after a few hundred yards of driving, the car feels absolutely normal again and then I won't see the issue until the next day. I have the car for a few more months before I hand it back so I would rather not have to spend a great deal of cash on it.

Cheers.