Judder at low revs when AC is on

[ally406]

'97 1.9 TD. Car was a bit of a heap when I got it, both belts looked like they were about to give up. Aux belt had run one groove wide of the crank pulley. I've always noticed a bit of an intermittent judder at low revs, but only when the air con is on. I've fitted a new timing belt kit, aux belt and replaced one of the aux belt tensioners (the other was fine). Everything runs straight and true with no unusual noises. It's also had a full air con service and the air con blows baltic cold air (so cold, I had condensation on the outside of my windows one day!). However the problem persists. It isn't bad, but definitely not normal. Anyone dealt with this before? I haven't inspected the lower mount, but I doubt this would be the issue as it's 100% fine with the AC off?

[Bailes1992]

Totally normal, my Focus also does this.
The A/C takes around 10bhp to run, basically your labouring the engine when your pulling off. You just need to give it abit more throttle

[ally406]

I know what you mean, but I think this is different. It's not necessarily when I'm pulling away, even driving along at 25mph, it's like someone nipping the handbrake on for just a second, definitely some sort of brief resistance. I also drive a petrol 406 with climate, no such problem. I suspect it's never had the AC serviced in its whole life. The guys at the AC place were amazed that it still worked. Now that it's been gassed and lubricated, maybe it needs a 100mph cruise* for a couple of minutes to get the compressor spinning and things freed up?




* on my private runway......located on the moon.