High Idle RPM - Help Me Solve This Mystery

[James523]

Hello BMW experts.

I m hoping someone here can solve my problem or tell me what is causing it.

I have a Nov 2010 BMW 523 Highline.

I installed 2 mods

1) Eisenmann Sport Rear Muffler 2 tail pipes 2 x 83 mm (LTA approved)
2) GruppeM Carbon Fiber Ram Air Intake System.

So this is the problem every morning.

I start the car n let it run till warm up. As usual the RPM is about 1000 n after warm up drops to 650 to 750.

I get in the car to drive off.

Once I engage D or R gear, the RPM shoots up again to 1000 to 1200.
It stay like this through out the whole drive.

The only way to get the RPM back to normal range is to switch off the car completely, wait few mins n start the car again.

Then everything is back to normal.

You can imagine how annoyed I get every time I use my car.

Any advice please?

 

[ac323]

idling valve issue?








cheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeers

 

[Citizen69]

Try manual driving. If the gear does not shift or drops down after a while even if you manually shift it, then it could be mechatronics issue (solenoids problem).

 

[Juzz Performance]

Have you tried checking the engine idle with the air conditioning in the off setting?

 

[James523]

Have you tried checking the engine idle with the air conditioning in the off setting?

Hello. Yes I tried that.
Doesn't help.

Will be sending the car in for a full check with all these suggestions.

 

[James523]

Try manual driving. If the gear does not shift or drops down after a while even if you manually shift it, then it could be mechatronics issue (solenoids problem).

Hello.

I have tried manual driving. Works perfectly fine.

 

[James523]

idling valve issue?








cheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeers

This is the most likely cause.
Will take a deeper look at this during the upcoming servicing.

 

[James523]

The other cause could be the fact that I changed my exhaust or something to do with the programming of the software. Will check further.

Thanks guys for replying and contributing.

 

[clemgoh]

523 has a n52 engine. No turbo six cylinder engine.

It has NO idle control valve from what I read.
And cannot find it anywhere in an n52

It should be controlled by Vanos and throttle body from the DMe.
With input from the various sensors for air flow temp and pressures.
So
Maybe there is an air leak or sensor issues or throttle body issue.

 

[James523]

Hi ClemGoh

Thanks a lot for the info. It will help me troubleshoot the problem better.

 

[Peter Ng]

i encountered this issue and had tried many ways and solved only after changing the DME.

 

[James523]

Hi Guys.

Sorry the late reply. Just to update you. The car is running so fine now. Like brand you.

The problem was actually the alternator. The alternator was not giving 100% though still running.

Changed to a new alternator and the problem stopped. The car engine will rev higher to compensate for the weak alternator.