Idling rpm for e90. Post and compare.

[alvinado]

Hi guys. I have an Idling rpm of 600-700 when a/c is off and 900-1000 when ac is on. Any idea if turning on the ac is supposed to add load to the engine and thus increase Idling rpm?

My observations are based on a warmed up engine. Not on a cold start as cold start Idling rpm tends to be higher and after that's goes into normal range. Btw, my rpm is not fluctuating, it just goes into the respective bands I posted on top with the ac on and off.

Any inputs from Bro here will be strongly appreciated!

Cheers!

 

[zhelinm]

Re: Idling rpm for e90. Post and compare.

Yes, idle with aircon turned on will be higher as the ECU will compensate for extra load on the system. AFAIK, the main purpose to prevent engine from dying off when the rpm comes back down rapidly with the a/c on.

Hi guys. I have an Idling rpm of 600-700 when a/c is off and 900-1000 when ac is on. Any idea if turning on the ac is supposed to add load to the engine and thus increase Idling rpm?

My observations are based on a warmed up engine. Not on a cold start as cold start Idling rpm tends to be higher and after that's goes into normal range. Btw, my rpm is not fluctuating, it just goes into the respective bands I posted on top with the ac on and off.

Any inputs from Bro here will be strongly appreciated!

Cheers!

 

[alvinado]

Re: Idling rpm for e90. Post and compare.

I learnt something again today! I love this place...

 

[seanskye]

Re: Idling rpm for e90. Post and compare.

Yes, idle rpm is always higher with a/c turned on as the engine has to work harder. For info, my engine idles at 600-700 with a/c off and 700-800 with a/c on.

 

[Red_Bean_Bun]

Re: Idling rpm for e90. Post and compare.

Aircon off - about 650 ish
Aircon on - about 720 ish

If your idle is 1000 rpm ..... Please send to WS for checkup.

Hi guys. I have an Idling rpm of 600-700 when a/c is off and 900-1000 when ac is on. Any idea if turning on the ac is supposed to add load to the engine and thus increase Idling rpm?

My observations are based on a warmed up engine. Not on a cold start as cold start Idling rpm tends to be higher and after that's goes into normal range. Btw, my rpm is not fluctuating, it just goes into the respective bands I posted on top with the ac on and off.

Any inputs from Bro here will be strongly appreciated!

Cheers!

 

[alvinado]

Re: Idling rpm for e90. Post and compare.

Aircon off - about 650 ish
Aircon on - about 720 ish

If your idle is 1000 rpm ..... Please send to WS for checkup.

OK I go check..

 

[alvinado]

Re: Idling rpm for e90. Post and compare.

ok, checked today while drive. My bad, my idling with aircon on is from 700-800 rpm. so I guess it's normal

 

[jacobang]

Re: Idling rpm for e90. Post and compare.

Yes, idle with aircon turned on will be higher as the ECU will compensate for extra load on the system. AFAIK, the main purpose to prevent engine from dying off when the rpm comes back down rapidly with the a/c on.

hmmm, i ever experienced engine dying when moving off and air con still remains on. looks like ECU gone kaput alr?

 

[zhelinm]

Re: Idling rpm for e90. Post and compare.

hmmm, i ever experienced engine dying when moving off and air con still remains on. looks like ECU gone kaput alr?

Depending on the vehicle itself, the idle air control might be implemented by a separate simple controller or controlled by the ECU. Either way, it works by increasing the pilot air flow of the throttle body. This pilot air flow is a separate air flow that is parallel to the main throttle body opening via the butterfly valve and works primarily to control idle speed. Usually, its the throttle body itself or the valves that requires some cleaning to remove any blockage that can cause errantic idling. Electronic controls are quite reliable and durable and last its lifetime.

Above comment are generic for all vehicles and for specific idle control mechanism, refer to your own model service manual or check with your trusted mechanic. =)

 

[BMW-GK]

Re: Idling rpm for e90. Post and compare.

I did a setting from WS via autologic and set it at 800rpm for both on and off of A/C.. so it wont go up and down....

What I know is if every time A/C compressor kicks in (ON) the rpm drop a lot and ECU have to compensate a lot (higher RPM) means compressor mati sooon... (just my own opinion/observation)

 

[alvinado]

Re: Idling rpm for e90. Post and compare.

I did a setting from WS via autologic and set it at 800rpm for both on and off of A/C.. so it wont go up and down....

What I know is if every time A/C compressor kicks in (ON) the rpm drop a lot and ECU have to compensate a lot (higher RPM) means compressor mati sooon... (just my own opinion/observation)

Is it better this way? Setting a universal rpm.

 

[BMW-GK]

Re: Idling rpm for e90. Post and compare.

it depends on individual...

I find it quite good... engine doesn't up down every time...

 

[easy]

Re: Idling rpm for e90. Post and compare.

At 800 rpm, FC would be higher, another possibility would be set the constant at idling at 720-750 which is what the default is with a/c on.

 

[Red_Bean_Bun]

Re: Idling rpm for e90. Post and compare.

Compressor won't mati because idle rate is fluctuating ...... Imagine what happens when revving ......

I did a setting from WS via autologic and set it at 800rpm for both on and off of A/C.. so it wont go up and down....

What I know is if every time A/C compressor kicks in (ON) the rpm drop a lot and ECU have to compensate a lot (higher RPM) means compressor mati sooon... (just my own opinion/observation)

 

[easy]

Re: Idling rpm for e90. Post and compare.

Compressor won't mati because idle rate is fluctuating ...... Imagine what happens when revving ......

I think what he might mean is that the higher idling every time the compressor kicks in may be a sign that compressor is weak and therefore have to work harder thus in turn causing the higher idling. Not sure if I'm making any sense (?) :ehhh:

 

[alvinado]

Re: Idling rpm for e90. Post and compare.

Then everyone's compressor is weak. Lol

 

[lenoir]

Re: Idling rpm for e90. Post and compare.

My idling RPM does not fluctuate, but w/o aircon on, it's slightly below 800, and with aircon on, it's about 900. is this within acceptable range?

 

[pegaki]

Re: Idling rpm for e90. Post and compare.

my RPM is fixed at 800rpm at D,P or N and with or without aircon