Air Conditioner Noise

[DRK]

Hi everyone,

I wonder if someone can assist (I've looked at the posts on topic, best I can tell). In the last few months the 4WD has started to make a noise when what I assume is the AC compressor kicks in. The air conditioner yields icy cold air no problems, and blows hard when the fan speed is increased. The noise sounds loudest on the passenger side, and can be heard inside and outside the car. The noise sounds to me like it cuts in and out in a very definite sense, and disappears when the AC is switched off.

Before I bought the car it had a new receiver/dryer put on and the AC was regassed and refitted. The noise sounds to me like a short, constant vibrating rattle, while something is spinning, and then it stops, periodically.

My first question is, does anyone know what this could be?
My second question is, does anyone know how to fix it?
My third question is, does anyone know whether leaving it will cause any damage? While it blows cold air, there seems no problem other than the noise - I might just leave it if it won't cause any other problems.

Cheers,
David.

[megatexture]

Isn't the fan on the passenger side? Could have something loose in it that's hitting the fan blades?

[megatexture]

Try with the fan on but aircon off and see if its still doing it.

[DRK]

No I don't think it's the fan, because the noise only happens with the AC on (and then only periodically, yet constantly) - and that makes me think it's not something like a leaf stuck somewhere. I reckon it might happen when the compressor cuts in, and stops when it cuts out.

[my third 256]

what about bearing on the compressor

[gaddy]

Maybe some crap in it they are mounted pretty low . And get a bit of bearing noise if been in the mud and water

[DRK]

Is there a way to test whether it's the bearing? Should a good dose of WD-40 have an effect? Any idea on how to tackle all of this - I'm trying to build up my limited mechanical skills!

[megatexture]

A hit of wd40 may give some temporary relief or enough to confirm its the bearing.

[Yendor]

If the noise is coming from inside the vehicle it could be the H block valve.

If it's more noticeable under the bonnet it could be coming from the A/C compressor.

Why was the receiver dryer replaced?

[GQ TANK]

What modle of patrol do you have, what motor?

Could also be the aircon idler / tensioner pulley (if your set up has one) - this is what failed on my gq and was a $15 repair

To test

1. Remove the aircon belt

2. Give the idler pully a spin - is it noisey? If so pull it out and either purchase a complete ass, or pull the bearing and go to a bearing place with it (this is what I did)

3, Give the aircon a spin is the bearing noisy - if its this you have a couple of otions

a. Take the truck to some one
b. pull the pully while the air con is implace (dont release the gas) and replace the front bearing

[mudnut]

Has anyone pulled the bearing? How hard is it to do in situ?

[sooty_10]

I've got a bit of what I would call 'bearing noise' coming from the front passenger side of the car too. I might have to pull the belt off and have a check. Keep us posted on what it ends up been. Also interested to know the extent to pull the pulley off insitu.

[salmon3268]

I had that problem and it was the blower fan which was stuffed replaced it and it works get now