Rough idle e70 x5 3.0

[leafsrule531]

I’m getting very bad rough idle when I start the my suv. I recently swapped out my mass airflow sensor which helped the problem a little bit but still not great. Sometimes the car even hesitated to turn on and turns rights off. The MAF I got is from fcp and it’s VDO so I know it’s a good quality one. I checked for leaks in the intake boots and all seem okay. Any other suggestions? It actually drives fine afterwards it’s just when I turn it on it idles very rough and sometimes turns off. My suv has 180k miles but it’s just one thing after another for this truck lately .

[andrewwynn]

Plugs, coil, dirty injectors are the most common faults for those symptoms. Also is that engine direct injection? I think only 35 and 50 but I've not worked on the 30 model.

[leafsrule531]

Originally Posted by andrewwynn

Plugs, coil, dirty injectors are the most common faults for those symptoms. Also is that engine direct injection? I think only 35 and 50 but I've not worked on the 30 model.

I put new plugs and coils about 10k miles ago

[andrewwynn]

I would pull a plug or two to inspect.

I had a set if plugs last lest than a year in m54. If you get stalling when engine is warm and no other symptoms and no codes it is typically the cam sensor. The other gimme is the icv.

[leafsrule531]

Okay so I just got home and tested something based off of a YouTube video. I had put a brand new MAF but if I remove the plug from the sensor my rough idle goes away completely! Does that mean that the new sensor I received is possibly faulty?

[andrewwynn]

It runs extra rich based on a lookup table when no maf so it can often be any fuel or air mix problem.

[leafsrule531]

Originally Posted by andrewwynn

It runs extra rich based on a lookup table when no maf so it can often be any fuel or air mix problem.

So probably not a faulty maf sensor ? I’ll be checking the plugs and coils next.

[andrewwynn]

It's possible but what are you using for scanner? You need to check the fuel trims and O₂ real-time. Also fuel supply can cause these symptoms

[newb2bimmer]

Originally Posted by leafsrule531

if I remove the plug from the sensor my rough idle goes away completely!

Typical symptom of a vacuum leak.

[andrewwynn]

I think the n52 uses an idle control valve and your symptoms align with that being dirty. (or defective).

Also the m54 would have similar symptoms when the cam sensor started having intermittent signal problems.