It's a 2009 Panda 1.2 Dynamic Eco.

The idle speed has always been rather erratic when I turn on the air con, but it seems to be getting worse now.

With the air con off, the idle usually sits about 1200 RPM according to the rev counter. When I turn the air con on, and drive around for a bit, the idle speed becomes wildly erratic. I have seen it drop as low as 800 RPM, and today it went as high as 2200 RPM while sitting at traffic lights with the gearbox in neutral. This speed isn't consistent - it may gradually get faster and faster, then it will suddenly drop down again.

Is this a fault, or just a quirk of the car?

Idle contol issue probably.

800isok

2200 isnt

Charlie

The throttle body uses a stepper motor to control idle speed. However if its going as high as 2,200, you could have an air leak between throttle body and cylinder head.

Did you solve the issue? Have same issue with a 1.2 8v GP... Thanks

Check the air con compressor first, turn it over by hand and see how easy it is to turn and that it makes several turns without sticking. It could be a sign of a back compressor. Car is reving high to try and balance demand. The fact it doesn’t do it with the air con off is the main indicator here.

If it all seems ok take it to an aircon professional to get the gas pressure checked, or you can use MES to check the pressure of the gas in the system.

TagSouth

Abkzed said:

Did you solve the issue? Have same issue with a 1.2 8v GP... Thanks

Click to expand...

Not yet. I will need to take it somewhere to get looked at - not a mechanic myself.

Went on a fast motorway & dual carriageway run this weekend and it behaved itself. I think that the problem only really manifests when it gets hot in urban stop/start traffic, or on a particularly hot day.

If it's had a gentle life from new it might well benefit from a few hundred miles of fast motor way "thrashing". My ex district nurse's Seicento went from not a especially economical art of Zen driving car to quite a reasonable little driver by doing that.

Just a little update.

I got the dealer to do an aircon service while they were giving the car its yearly service. The car still pongs of antibacterial spray weeks later. But the engine revs seem a lot more stable.

That said, I don't suppose the engine is getting anywhere near as hot as it did during the summer. I'm now using the aircon mainly to demist the windows.