I've done some searching and I've found variations of my problems but not my mix of symptoms. I'm hoping someone here can shed some light! We have a late 02 XC70, model year MY03. It's got roughly 175,000km on the clock and all-in-all, it's a fairly good, reliable car. But, we're getting a problem that shows up more when the aircon is on.
My current theories are:
- coil pack
- aircon clutch (well, that's my brother's opinion
Symptoms:
- you can hear the engine surging (not sure if that's the right term) and it cycles through every few seconds
- when the engine sounds the loudest, you can see all lights on the car dimming
- rev counter hold steads, usually at 800RPM, sometimes at 600RPM
- when it's moderately bad the car will try to bunny hop when driving at walking pace (reversing, petrol station etc)
- when it's really bad, it's almost moving the car forwards even with the foot brake engaged (not handbrake/e brake)
- seems to be worst after having the car off for a while and then getting back in
- sometimes the surging goes away when shifting the car to manual shift mode
- the surging is reduced if you turn the aircon off
- the surging will go away if you turn the whole climate system off (turn the fan dial fully to the left)
Any thoughts?!
