Air Conditioning

[pridbor]

I have just begun to notice a noise from the A/C compressor. It's clearly related to it as the sounds disappear when the A/C is turned off.

I changed to a different "gas" than the R134 which the car came with from factory some 4 months ago, R12a which is supposedly compatible with the R134.

The unit still cools great, but I'm wondering if there's a common trait with you gents? My MO 04 has 85k miles on it and generally works fine.

Thanks for any support

[Pilgrim]

No noise here. IME noise from an AC compressor tends to be a bearing of some sort, or a clutch that's having problems engaging. On most compressors the clutch can be replaced without replacing the compressor or opening the system.

Keep looking for a pattern - the noise may have to get to a certain level of consistency to be able to diagnose it.

[Eric L.]

Check your AC pressures - you will need the specs from the factory shop manual (if you don't have it, buy it) - the pressures listed on the cans of the top-up recharge kits sold at auto stores report numbers way too high. If you overcharge the system, it will be both a strain on the compressor (hence the noise) and your AC will not cool down as well (if at all). I'm guessing an overcharged system here.

[pridbor]

The noises seems to be "mechanical" e.g. lack of oil in the compressor so I agree with you, a bearing it might end up being.

I have previously, on my Citroen, overfilled only to find that it cooled less, so I got a lesson there. I checked the low pressure yesterday, it around the 28 psi at 1000 rpm, which is what the manufacturer told me on the phone where it wants to be. I'm away from home a lot so the car has stood still for 1 or 2 months at a time, and I'm a noise "fanatic" i.e. I hear noises everywhere and I think when I get back from a trip, that the noises are "new" and thus I pay more attention to them than if I was driving the car every day.

But the noise seems a bit too loud to me to be any good, so I will monitor it for a while.

Thanks both

[zebelkhan]

Check the idler pulley for any play.

[pridbor]

Originally Posted by zebelkhan

Check the idler pulley for any play.

Wouldn't that produce a noise even if the A/C wasn't on? or is it the extra load that might tip it?

And that begs another question, when do I change the belt to prevent it from breaking happening far away from a dealership?

Thanks

[Eric L.]

Originally Posted by pridbor

Wouldn't that produce a noise even if the A/C wasn't on? or is it the extra load that might tip it?

And that begs another question, when do I change the belt to prevent it from breaking happening far away from a dealership?

Thanks

A belt with noticeable cracks on the ribs should be changed. Figure every 60,000 miles, at the very minimum.

[pridbor]

Originally Posted by Eric L.

A belt with noticeable cracks on the ribs should be changed. Figure every 60,000 miles, at the very minimum.

With 84k that makes me overdue. Will get one and replace.

BTW are there more belts, it looked like 2 when I cast a casual glance, more? Might as well do them all at the same time

I assume that it's "an easy change" but is there some writeup here on the procedure?

Thanks again all

[Eric L.]

Originally Posted by pridbor

With 84k that makes me overdue. Will get one and replace.

BTW are there more belts, it looked like 2 when I cast a casual glance, more? Might as well do them all at the same time

I assume that it's "an easy change" but is there some writeup here on the procedure?

Thanks again all

I am not aware someone here has written up the procedure but one thing that is important is to have a tension gauge to make sure the belt is at the right tightness. If you don't have one, I suppose you could buy one, but putting on a belt is something I am willing to pay an hour's labor for since its tight working around that area of the engine bay.

[pridbor]

I was quoted $145 incl belts a few hours ago, and yes it looks a little tight around the sides there.

I have a very sharp female as assistant maintenance manager at the dealership, and she has been very good to me in the time past so yes I'm going to have my dealer do it

I'm also going to ask that they check the Idler and other items attached to the belt for any slack worn bearings and so while the belts are off, in the hope that it's just a simplething

Thanks again

[pridbor]

Just wanted to let you in on my results.

I had the 2 belts replaced today by the dealership ($140) and gone is the noise, i.e. it had nothing to do with the A/C. Now runs smooth like before.

Upon my request they also checked the Idler arm and other pulleys around there and found nothing.

Thanks again for the suggestions

Live and learn