Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[harpersimon]

I always assumed that the climate control is in Eco mode I.e not running compressor when Eco is pressed and displays
Is that right? My car seems to run smoother with Eco off at idle and labour more when Eco is on. Like they are reversed?

[Kevin Wood]

The idle speed is increased when ECO mode is deselected due to the greater load from the AC compressor. That's probably why it seems smoother, but you have got it the right way round.

Kevin

[harpersimon]

The idle speed is increased when ECO mode is deselected due to the greater load from the AC compressor. That's probably why it seems smoother, but you have got it the right way round.

Kevin

Er.. no.. I don't have it the right way around.. I don't think
I understand what you are saying, as the expected result when you de-select ECO would be the idle would drop as the compressor loads the car -  but perhaps am not clear with my Eco on/off description.
So.. With ECO showing in the display, i.e. ON, and NOT runnnig the AC compressor, my car seems to idle like it IS running the compressor.
When I De-Select ECO so it does NOT show in the display, and therefore IS running the compressor, my car seems alot happier and under less load at idle
What I am saying is with the aircon on the car is very smooth, and when I turn it off the revs drop abit, appear under load and it idles less consistently. Not rough by any real means, but not as silky smooth as when Aircon is on.
Go figure!? (I have tested that its not some miswired switch etc as I get V cold air when NO ECO shows (AC on)

[Kevin Wood]

I think you have got it right.

With air con compressor on the idle speed is raised to about 600-650 RPM.

With air con compressor off the idle speed is 450-500 RPM.

Idle speed is under control of the engine ECU so the extra load doesn't drop the idle speed. The reverse happens as the ECU raises the idle speed.

Kevin

[harpersimon]

Ah!LOL
So it's the ecu compensating that makes it appear to idle smoother when AC is on. Gotcha. Makes sense now and sorry about the crap confusing description!

[2woody]

yep - the ecu actually requests a higher engine speed, to give a bit more torque and stability to run the air-con ( up to about 25HP at its most )