Rough Idle

[Enigma335i]

Hi Guys,

My E92 335i picked up a rough idle about a month ago and it is really starting to annoy me.

It has been into BMW twice already and they havent resolved it, they keep adjusting injector timings but the probem persists.

It is bad under cold start but equally bad if not worse once hot, feels like im driving an old school muscle car when im standing at a traffic light. Car gently shakes and rocks every now and again, can feel the uneven revving.

any ideas what could cause this?

 

[boost3d]

Not sure what causes this but after a visit to the carbon doc I can assure you that your car will idle alot smoother ...

You can read up on the review I posted if you want more info

 

[OppositeLockMT]

Our E60 had a similar rough idle, sounded like a muscle car at idle. She was only running on 4cylinders because of 2 faulty coils.

 

[cOlDFuSiOn]

Perhaps a faulty MAF sensor?

 

[David1]

Hi Enigma,

I have the exact same problem, every now an again it will 'shudder' an my car is currently in for the 2nd time or this problem. The last time they reset the adaption or something and it helped alot. I keep asking them to please check the coils, plugs and injectors. We will see how it is once it comes back today.

Just off topic what does a MAF sensor do and could one clean this at home, or is it is it only something the dealer can do?

 

[Turbo 1]

They replaced 6coils 6injectors and 6 spark plugs on my car....that solved my rough idle immediately

 

[mo335]

Check and replace your plugs. More so if you are running a tune.

:thumbs:

 

[Enigma335i]

Thanks for the replies guys, my car developed the rough idle a little while after i removed the JB4, car was fine after that. Car is running stock at the moment.

I have had a few items replaced under service plan lately...cylinder head, exhaust, radiator etc with the turbo and injectors having being adjusted as well.

really not enjoying my car at the moment with this idling issue now

 

[dino_rox]

any performance issues though with the idle so rough ?

i had issues with a coil as well

 

[Enigma335i]

any performance issues though with the idle so rough ?

i had issues with a coil as well

Quite honestly, the performance seems fine or if it is off, it isnt very noticeable.

 

[Photokid]

Thanks for the replies guys, my car developed the rough idle a little while after i removed the JB4, car was fine after that. Car is running stock at the moment.

I have had a few items replaced under service plan lately...cylinder head, exhaust, radiator etc with the turbo and injectors having being adjusted as well.

really not enjoying my car at the moment with this idling issue now

Sorry if I'm a little off topic, but do you know what caused the repairs to the cylinder head etc?
Did it have anything to do with the tune or jb4?

 

[Enigma335i]

Thanks for the replies guys, my car developed the rough idle a little while after i removed the JB4, car was fine after that. Car is running stock at the moment.

I have had a few items replaced under service plan lately...cylinder head, exhaust, radiator etc with the turbo and injectors having being adjusted as well.

really not enjoying my car at the moment with this idling issue now

Sorry if I'm a little off topic, but do you know what caused the repairs to the cylinder head etc?
Did it have anything to do with the tune or jb4?

Nah, it was an issue before I had the jb4 on, car seemed to be going through radiators till they found the crack in the cylinder head. Only had the JB on very briefly

 

[Twinz]

I would look at the issues below. Its very common for the x35 motors to behave like your describing due to bad plugs/coils/injectors. Of course there can be another reason but its good to start here.

They replaced 6coils 6injectors and 6 spark plugs on my car....that solved my rough idle immediately

 

[Ralf*]

on my V8 E38 740i the roughness is due to oil leaking out of the tappet cover gasket and finding its way into the spark plug housing and creating a sort of short.

I also suspect that I have a vacuum leak,, and my MAF and/or ISV were playing up....still not sorted, just living with the rumble for now.

 

[AeroEng]

I had the same issue earlier in the year and the JB threw a few misfire codes. Removed the JB and still had the same issue - rough idle in the lower RPM range.

Also thought it would be coils, plugs or injectors but BM did a software update and it seemed to resolve the issue.

Running smooth for a few months with the JB back in.

 

[Enigma335i]

yeah its time to book it back in again..have a feeling third time around they might do a bit more hardware replacing instead of tinkering with timings

 

[boost3d]

Maybe it's time to change dealers and try someone who would be prepared to go that extra mile .... Don't know about you guys but finding it harder and harder to get good service from dealers

 

[Twinz]

Yep...i think George Smooth should open a dealership & we can all support him. :thumbs:
Because of MP we forced to check in at the official dealerships and they know that...:bangdesk:

Don't know about you guys but finding it harder and harder to get good service from dealers

 

[Enigma335i]

Yep...i think George Smooth should open a dealership & we can all support him. :thumbs:
Because of MP we forced to check in at the official dealerships and they know that...:bangdesk:

Don't know about you guys but finding it harder and harder to get good service from dealers

Agreed!

Regardless of the outcome I think i'm going to pay him a visit to clean the carbon build up anyway.

 

[bmsportzn135i]

Yep...i think George Smooth should open a dealership & we can all support him. :thumbs:
Because of MP we forced to check in at the official dealerships and they know that...:bangdesk:

Don't know about you guys but finding it harder and harder to get good service from dealers

Agreed!

Regardless of the outcome I think i'm going to pay him a visit to clean the carbon build up anyway.

Now thats a good idea. You wont be dissapointed!