Question with air con systems (156)

[avim]

I was looking at a 156 manual TS on the weekend and noticed that the revs would rise and lower very slightly as soon as the air conditioning was turned on whilst the car was at idle.
Is this normal or a cause for concern?

[John Hanslow]

That's normal, happens with my car.  happens more with older cars of any description.  As soon as the aircon is engaged, the belt powering the compressor takes a small amount of power from the motor which drives it.

Good luck with your future purchase.  Be mindful of other 156 purchase threads in rthis forum, and get the car checked out by an Alfa Specialits.

Cheers.

[avim]

Thanks for the reply John.
The guy said that it was an emissions control thing and I wanted to clarify this point.

[meizhak]

will have a idle control motor or solenoid that compensates for loads on the engine