Aircon noise / regas cans

[Gman2]

I've got an audible whine as soon as I switch to aircon that immediately ceases when I switch to ECON. I've assumed previously on a post that it's the bearing in the compressor but could it be the fan causing the noise? The whine is on constantly with the aircon.

If it is the bearing then I know from posts that a regas with the lube has been known to sort. There has been mixed feelings with regard to the DIY cans but I've noticed the Halfruads kit has the oil. What I have noted that in the R75 Haynes manual they include the DIY cans as a "top tool tip" :confused:

[Greeners]

spend £50 or £60 and get a local A/C specialist to have a look, if it's cold, then the gas is probably ok.

Anything in a can won't solve your problem.....

[Livermpj]

I think the whine could be from the thermostatic valve inside the car. IIRC it oscillates back and forth to maintainan a constant temperature in the evaporator.

Mine started whining after a gas top-up (carefully done by a workmate who has pressure gauges, manifold & gas). Apparently the valve adopts a different working position as the pressure inside the system changes, and topping up causes an increase in pressure. After a while the valve beds-in, and quietens down (mine has anyway).

Right from new, there's always been a faint noise with aircon on, I think it's a "characteristic" of the car.
HTH, Pete.

[chris75]

Sorry if I'm stating the obvious , but if this is not a new noise then might it not just be the fan , working as intended ?:shrug:
The fan is quite audible , and goes off with the econ setting..........

[James.uk]

Personaly I prefer to leave air-con stuff to the experts, mine is booked in for Monday pm due to the belt beginning to screech when the air-con is turned on, I bought a 2nd hand Compressor for £75 (with 6 month warrentee) last week just in case --- :o

I know the aux belt is ok, it was replaced only 4 weeks ago..
.

[Gman2]

Sorry if I'm stating the obvious , but if this is not a new noise then might it not just be the fan , working as intended ?:shrug:
The fan is quite audible , and goes off with the econ setting..........

Possible but it's on constantly when aircon is selected and the whine increases with the revs. With the ZTT the fan comes on but is discreet and intermittent :confused:

[Gman2]

Ok this annoying droning is the fan and not the aircon unit and is quite audible within the car. When I activate the aircon without the engine turning over it's silent. Engine on and aircon on then the fan kicks in and drones away but ceases when ECON is selected.
I get a tad confused with the fan set ups - the R75 is an 02 plate so I assume it's a 3 speed fan and that they stay on constantly with the aircon on? The ZTT is 04 and so will this be 2 speed and as said previously the fan is intermittent with aircon on and is hardly noticeable in the cabin.

So a noisy fan - any cures, is it a sign it's on the way out or do I live with it?

The aircon could also do with a regas but advice taken re a specialists.

[T-Cut]

Ok this annoying droning is the fan and not the aircon unit and is quite audible within the car. When I activate the aircon without the engine turning over it's silent. Engine on and aircon on then the fan kicks in and drones away but ceases when ECON is selected.

That's the correct operation of the fan with A/C running. Applies to both 3- and 2-speed systems.

The ZTT is 04 and so will this be 2 speed and as said previously the fan is intermittent with aircon on

The slow speed resistor has failed. The intermittant fan is the emergency system tripping in to prevent a serious overheat. You really shouldn't run the A/C in this condition or you may do expensive damage. You need a replacement resistor. You can buy a pre-made up kit for around £30 or the basic unit for a fiver or so.

http://i5.photobucket.com/albums/y191/waveguide/Fan_Resistor.jpg

Depends on your DIY skills, but both require the front bumper to be removed. The forum is full of info on these jobs.

TC

[Gman2]

Blimey - thanks for the info T-Cut! I'll get it sorted pronto :bowdown: I suppose nought can be done with the droning noise from the fan on the R75 - is it a worn bearing.....:shrug:

[butty]

You may also get a whining noise from the compressor itself - this is evident by the whine changing pitch with a slight increase in engine revs. Mine appears to be most noisey at arround 1000 rpm and goes silent at about 2000rpm. I dont know if thats normal, but it's done it since new (55k miles ago). I put it down to characterisitc too.
Mine still cools well though - thank goodness as it was 33 degrees whilest down in Norfolk today!

[Fraser Mitchell]

If the whine varies with engine revs it will be coming from the aircon compressor, because the cooling fan motor runs at a constant revs unrelated to engine revs. Pressing 'Econ' switches off the air-con and hence the compressor, so the compressor stops, causing the whine to stop as well.

I had a similar whine last year, and it was cured when Lates replaced the compressor with a new one during the cambelt change. Having said that, there was very little oil in the old compressor, so adding oil may have cured it. In my case I bought a new compressor from SMC Trading for a very good price, so did not test whether adding oil made any difference.

[Gman2]

Thanks for that lads. I wasn't convinced it was the fan but wasn't sure how the compressor varies with the revs - but that's exactly what I've got. The aircon isn't as cold as it should so a regas with lube will be the first port of call then I'll take it from there.....:)

[Gman2]

Hey hey - job done! Went for the full aircon treatment at Nationwide Autoservices today that includes dye test, lube, refresh and regas. It was only cooling to 5C! Ok it set me back 70 notes but now the cabin is well chilled and the compressor has stopped droning so well worth the spend :)