Aircon

[Furni]

Hello all listening to my engine with the lid up when the aircon kicks in there is a click or clonk sound engine revs increase
is this normal? Your opinions please.
Thank you


Furni

[commievid]

tl;dr: yes.

The click will be the relay turning on the air compressor, and the resulting rev increase as a result of the compressor adding a bit more drag to the engine.

Although I notice on MR2's that the rev's will increase whether the compressor is actually on or not, presumably the ECU just tells it to increase it when the light is on.

What's much harder to see is whether the compressor is actually spinning, although if you hear clicking, it probably is.