lumpy idle when aircon is switched off?

[Jamz3k 0]

I noticed a few weeks ago that when i switch off the aircon in my 147 the idle becomes lumpy although the revs don't seem to rise or fall at all during the lumpiness?

 

Any ideas?

[Smaky 73]

I would think that you have a sticky breather valve and the extra strain on the engine during A/C operation is preventing it from hunting. Replacing the valve may solve this and there is a guide with part numbers in the Engine section.

[Jamz3k 0]

cheers smaky, does this have any adverse affect on driving the car until I fix it?

[Smaky 73]

If you run with A/C on then it'll use more fuel.