[briwyle]

Hi. My bmw 320d m sport has recently started to fluctuate the revs in tickover but it doesn't always do it has anyone else had this problem ? And if so has anyine solved the issue or know what causes it? Had 2 diagnostics already but nothing has come up .going to get it into bmw soon if i cant get it sorted trying to avoid bmw because there diagnostic charge is over 100 pounds.


Thanks in advance

Mark

[beambeam1]

Vacuum leak of some sort. Chasing a similar issue in my car at moment.

[briwyle]

Cheers for the reply my mate has mentioned he thought it was an air leak or something butim not convinced as i would of thought it would do it all the time because the leak would always be there.

[Kuroblack]

Is it just the idle, or is it rough/hesitant on light throttle? (Typically just after you've started the car and moved off)

[briwyle]

Its just on idle

[old grey steve]

If it's an idle issue and if as I think it is yours cars an N47 spec 320d they can suffer from various issues

Rough idle when we see them and we see shed loads perhaps one of the most issues can be down to the glow plug controller usually you get the fault code glow plug activation after say glow plug cylinder 1 or whatever, plus on the relay if you get/see a communication fault dead cert this is playing up, other issues can centre on the manifold where commonly there's one of a few faults within it plus the EGR valve/coolers can play up on these as well but purely on the idle the glow plug relay would be a firm starter for 10 IMO, but as always get it checked out first and thoroughly

Other things worth looking at if yours is an N47 spec is soot around the plastic intake manifold as they can suffer various issues and basically can fracture and seperate or due to heat/pressure/contamination literally explode from inside out effectively punching a hole in the manifold and if this is just starting to take place it can lead to various issues including erratic idle and soot traces on the manifold or on the acoustic under cover near the intake manifold are a sure sign and to me when this happens you can get light throttle hesitation in some cases and as for the EGR set up seen a good few units let go causing cross contamination for the manifold

Same kind of issues go for the N57 spec too

[briwyle]

cheers i've got it booked in at bmw for monday just for them to run a diagnostics and also a mechanical check just so i can determine what it exactly is without spending loads replacing parts and finding out its not the one i replaced it becomes quite costly then . thanks for the reply