RPM - Help Needed

[cas]

my ride is e36 intermittently if i stop the car at a traffic light the RPM will drop below 0.5 then back to slight below 1, sometimes when i push to D it will have the same prob, its very rare, only happen sometimes, is this normal, if not what could be the problem ?sifu's pls advise !

 

[Lee36328]

Normal is rock steady all the time.

Check the idle control valve, as well as the throttle position sensor, as indicated below.

 

[cas]

bro.. how much does it cost to replace the sensor, and its intermittent is it any prob if it not replaced

 

[Lee36328]

The above illustration is for M42.

This one below is for M52, item labeled no. 6.

 

[Lee36328]

bro.. how much does it cost to replace the sensor, and its intermittent is it any prob if it not replaced

Cas,

Searched, and found you are driving a 318.

This item seldom fails. It is more likely dirty.

Go to your regular workshop, and have it cleaned.

To replace, it costs around RM600+