Weird engine noise

[Javaman365]

So the XC90 is settling into life with us.
A few times now, while at Rickover, there's this loud noise, like a electrical motor kicking in for a few seconds, then out. I thought maybe cooling fan, but after a very short journey? And only intermittently, but very regular?
Could it be something combustion related? Lifters, swirl flaps arm?
I had a Vida print fine prior to buying the car, no faults, and I guess the best thing to do would be to run one again when I've got my DICE and set up later this week.
But any knowledgeable guesses welcome at this point to peruse my wallet and nerves to discuss with the supplying dealer in the event its something serious....

[4x4]

Air-con compressor

[Javaman365]

Could an AQS sensor internal fault have something to do with it?
And if not, why is it so damn loud?

[john langrick]

Hi, I also plumb for Aircon compressor.

You could try just switching a/c off or disabling it by removing the activating wire, if it was like mine, it has a bullet connector.

Mine had faulty bearings, a very loud 'burring' noise but only when activated.. I thought my starter was faulty too as it appears if cycles the a/c compressor at start up wether a/c on or off. Replacing the pump stopped both noises completely.

John l

[Javaman365]

Dare I ask a/c pump prices? Gulp.....

[tonygreen1966]

I got an a/c pump off ebay for £190 ish. It’s now 18 months old and works fine. Remember to get all new o rings(£30 ish dealer) and buy a new drier(£15 ebay). Easy job. Drier is next to the radiator- just follow the pipes. My a/c pump idler/freewheel bearing went. It ran ok with a/c on but when switched off the freewheel/bearing was goosed and it knackered the belt, the belt overheated due to friction and melted my plastic tensioner pulley and PAS pump plastic pulley! While I was changing all this stuff I also changed the alternator pulley which has an internal clutch that sometimes fails which then causes belts failure etc. Mines was ok but changed it anyway- alternator comes off with a/c pump anyway. You may want to change this alternator pulley as they fail after a while. You’ll need a tool(£10ish I think) to remove alternator pulley. And of course change the belt while you’re in there – and maybe the tensioner as they can also fail and the belt debris can get in the timing belt cover and cause timing belt failure. Good luck.

[john langrick]

Hi, I ordered a nissens unit from eBay

https://www.ebay.co.uk/itm/274145431640

Earlier that year I replaced the condenser with a nissens unit too as that was leaking. The compressor came complete with drier.

You also need to budget for a regas. I got my indie to replace mine as there is also environmental issues in draining the a/c.

John l

[john langrick]

Oops, typo. The condenser came with a drier.