Floating RPM when AC on

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kapilamuni
Posts: 6
Joined: Wed Feb 15, 2017 1:50 am

Floating RPM when AC on

Postby kapilamuni » Thu Jul 05, 2018 10:42 pm

Hi,
My car is a BMW 525TDS diesel . The AC functions normal with very cold air. Since recently when AC on the engine RPM fluctuates up & down. This has no effect on the cooling efficiency but very annoying. I got the idle RPM increased from standard 750 to 800 , but the problem remains.
The compressor is DENSO 10PA17.

Your advise appreciated.
kapilamuni
Posts: 6
Joined: Wed Feb 15, 2017 1:50 am

Re: Floating RPM when AC on

Postby kapilamuni » Sun Jul 15, 2018 7:12 pm

It seems no one experienced this type of behaviour before. :(
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bohica2xo
Posts: 558
Joined: Wed May 11, 2016 4:12 pm
Location: Las Vegas, NV

Re: Floating RPM when AC on

Postby bohica2xo » Sun Jul 15, 2018 8:34 pm

Not an A/C problem.

Engine idle speed is controlled by the ECM. Take it to BMW & have them read the codes, something is not functioning properly in the engine controls.

Is this car located in the USA?
kapilamuni
Posts: 6
Joined: Wed Feb 15, 2017 1:50 am

Re: Floating RPM when AC on

Postby kapilamuni » Mon Jul 16, 2018 7:23 am

No the car is not in USA.
I have the software and through that only increased the idle RPM. No point in going to the dealer, they don't care about older vehicles. :evil:

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