Engine: S60: Whiring noise coming from engine

[Brendan W]

If the system is working normally, with the ignition on or even with the car idling, disconnecting the sensor should put the rad fan on as the car will think it has failed or gone open circuit somehow. Another thing to check there is the voltage at the plug. I think it should be around 5 Volts, it is on most other cars.

[cheshired5]

Originally Posted by Brendan W

I think it should be around 5 Volts, it is on most other cars.

It is.
One plug contact is ground, the other 5V.

[andylane1]

I'll try all of the above when I get my Multimeter back from the person I gave it a lend to. Meanwhile there have been developments. I started the car again from cold and the fan came on full tilt straight away. I checked to make sure all the cables were seated correctly. They were. I then turned the car off and connected my Wifi Elm OBD reader coupled to an iPhone app called OBD Fusion. it reads some but not all of the information from the Volvo. It was saying there were no trouble codes. I started the car again and again the fan came on. I then turned it off and cleared all trouble codes through the software even though there were none. I then started the car and no fan. Tried twice more and again no fan. I've no access to a Vida dig tool or software so I cannot go any deeper than this but with this new information does anybody have any idea what it is?

Thanks

[Brendan W]

I think the technical term for that is a glitch. Watching brief. Have seen erratic behaviour sorted by resets, battery disconnects and so on.
If it's serious it will come back.

[andylane1]

Finally updating this post. I finally got around to doing the job. Brendan you were spot on replaced the Aircon bearing and low and behold it was lovely and quiet. Its like driving a different car.

Now advice to anybody doing this in the future.

1. I did it along with an overdue PCV and oil trap change. I highly recommend it as with the intake manifold off you have a load of room to move about. Now doing that also brings other problems to do with some of the bolts on the manifold but doing both jobs complement each other.
2. Make sure you have the correct tools. DO NOT attempt this unless you have a a decent toolkit about and if possible the benefit of a Mechanic (my father)
Speaking of tools don't make the same mistake I did and assume that I could not get the by all accounts amazing tools that D5Meisters has made for this exact job. I assumed living in Ireland it would be a pain to get them across not to mention silly money for postage. Don't, speak to him and sort it. It would have made my life so much easier in doing this. It easily added another 1-1 1/2 hrs to the job by not having them. That being said it pays to know somebody that is great yet careful with a small lump hammer to get the A/C clutch off. Again refer to point 1 without the manifold off I would not have been able to do this.

Hopefully this is helpful to somebody moving forward. Thanks to all the advice from the lads It did make this job a lot easier and saved me 3/4 what I paid for the car had I gotten Volvo to do the job.

Andy

[Brendan W]

Steve's tools are the job and yes the postal system works. It is so much easier when you know you are getting kit that actually works.
At this rate those tools will have more miles on them than any of the cars they visit

[andylane1]

By all accounts they are well travelled and rightly so. Ah well hindsight... with any luck I won't need them in the rest of the time I have with the car. thanks again for the advice Brendan.