ROUGH IDLE at 30k?

[135BANDIT]

Hi Crew,

Our 2010 135 is now experiencing severe rough idle, we have just ticked over the 30k mark and sadly 2 months out of the time based warranty limit.

Any ideas on what the prognosis might be and whether BMW will provide any warranty assistance?

Also if and i mean IF , we had a JB4 fitted, should we remove this from the vehicle prior to returning to the dealer? Or will VALET mode be okay.

Thanks in advance

JD.

[racer_x]

Does it start OK? If not, might be a HPFP issues.

Does it seem down on power? Maybe a HT lead/spark plug/coil pack on their way out.

[UR25IO]

is that a N54 or N55 engine?

[drjekl]

Have the plugs been changed yet?

Does it chuck any CEL's?

Does it idle rough on another map?

[135BANDIT]

Thanks for the feedback

Its a N54 , starts okay and appears fine once warmed up , it has thrown an intermittent CEL, I have not swapped maps and will try this tonight.

[Dackelone]

Could be anything really, bad: spark plugs, vacuum leak(oil cap not seated, vacuum res lines popped off, valve cover gasket leaking?,ect), bad coil(s), injector(s), or carbon buildup. ???

You really need to read the code and go from there.

[VGR00]

"If" a JB4 was fitted, remove it ASAP and take it to the dealer. 30K is not a lot and being just out of warrenty they might offer some form of good will.

[n2djazz]

Originally Posted by 135BANDIT

Thanks for the feedback

Its a N54 , starts okay and appears fine once warmed up , it has thrown an intermittent CEL, I have not swapped maps and will try this tonight.

I have an '09 135i with 45K miles. I changed the plugs a couple wks ago thinking it would correct my stumbling issue but it didn't. Have you gotten your problem corrected? If so, what was the problem?

[135BANDIT]

Hi No its still stumbling at idle , its back to the dealer for me .............. I feel its a leaky injector but the dealer believes my car is not part of the injector program

[racer_x]

Maybe take a video of the issue on your phone and post it on YouTube. How long has the dealer spent trying to diagnose the issue?

[Jeef Beef]

Probably coils. HPFP should give you some hard starts.

[135BANDIT]

Just git the car back - even though My VIN didn't register faulty injectors , they replaced 3 injectors and are now telling me Morning starts will be a breeze...............

[RadiuM]

Originally Posted by 135BANDIT

Just git the car back - even though My VIN didn't register faulty injectors , they replaced 3 injectors and are now telling me Morning starts will be a breeze...............

Same, except mine was out of warranty so I just did it myself (3 injectors, bank 1). Now it starts without a hassle on near 0degree nights.

edit: Having said that, when it was running "rough", the computer was actually dropping up to 3 cylinders and leaving them off so it sounded like some demented wrx on roids.

[BrokenVert]

With a tune the plugs need to be changed every 25k miles. So I'm going to bet thats your problem.