D5 (2005 on) Help please- rough XC70 D5 idle with AC off?!

[37 RUBY]

Originally Posted by Decky62

The interior lights also flicker slightly when it idles rough. Any help appreciated

I've fetched my box of clutching straws out of the toolbox and picked one...is the over-run clutch pulley on the alternator functioning correctly ? Perhaps the load from the AC when its on, masks the issue?

I do have other straws to clutch at too...if you have fluctuating voltage as indicated by interior lights, other components will do to - fuel pump, crank sensors. That list is endless. Perhaps put your voltage meter on at battery to ground then again at alternator power connection to ground. Also try running an alternative ground to see if its an earth issue. Surely a voltage fluctuating would also present within the fuelling and emissions control systems too.

In the meantime, if you need a few more straws to clutch at, you can borrow my box.

[marZiano]

I'm scratching my head and fighting with the same problem. P and N shaking, unburnt smell on exhaust (right from the start), missfire-like sounding...

VIDA shows no errors related.

Cleaned EGR valve and throttle body with no improvement. Injectors checked because oily aspect of #4. Wiring harness, too. Nothing helped.

I noticed interior and exterior light dimming, even when engine is cold, pointing me in the direction of alternator, or control module (ACM), or clutch pulley... But I don't know if this could be the cause, or just a symptom.

Another symptom: engine starts fast and smooth when cold, but when it's warm it cranks for a little more time than normal. And when I press the button to shut off, it shakes so badly. Nothing near a soft stop.

I'll keep looking and thinking.

[Decky62]

I didn’t notice this had run over to another page. Thanks for your help, I had the alternator changed because of the flickering lights awhile ago. Made no difference. Crank sensor I also changed ages ago and it still idles funny. I did wonder if it had anything to do with the heater, fan or ac compressor. I have a growning noise inside when the ac is on. If the ac is off but I still have the fan on I have no noise?!