A/C noises - recharge or replacement?

[graciebrother]

Hi,

My First post. Hope this works. I've been reading this forum for a while now and figured it's better to get involved!

A month or so back my 1998 Sport started making a low groaning noise when the A/C got switched on. It gets louder when I turn the A/C onto the Max setting. I don't do to many long trips but the last I did the AC was working OK but something sounded like it was struggling. I'm wondering if the system needs a recharge. The sound did go after a while, bt not sure how long into the trip it took.

I've searched the forums for similar but didn't uncover a matching thread, apologies if this is somewhere I haven't seen yet. Any thoughts?

Many thanks.

Kyle

 

[Gus Gorilla]

Welcome to the forum,
If your A/C were undercharged it would more likely cause a fast cycling clutch. The groaning could be the compressor. Check how the noise is under the hood. The first step to fixing an A/C system is checking the system pressures. If you can find someone with a set of gauges to check it they will know what the pressures should be and likely know what you need.

 

[robertoa1a]

When you say a/c noise, what are you talking about? A bad compressor or over charged system can break your belt and leave you stranded. Lucky for you, a new compressor cost less in the X than other vehicles, and is not as hard to change.

the troubleshooting procedure goes deep and you have to provide more info. about the problem and your skill level.

 

[graciebrother]

Thanks for your quick replies.

The noise is coming from in and underneath the glovebox on the passenger side. It doesn't sound any different nor does the location seem to change when accessed from under the hood. The noise almost sounds like the system is struggling to push the air through and having to work harder. The amount of air being pushed through appears to be fine though and it does getting reasonably cold. Could it be a tear in a hose?

I'm unsure if it's any use but I recall a month or so before this (may have been shorter) the A/C when turned on blew out hot air. It was as if switcher / mixer got stuck. Again not sure if there is anything to read into this as it appears to have fixed itself and the problem has not returned.

My skill level. Novice. I take it to the mechanics for most things!!

Thanks again.

 

[robertoa1a]

Having a set of gauges on it tells a lot for starters. Mine makes a noise when I shut the vehicle off but has always worked well. There could be air in the system, the orifice tube could be clogged, or there may be an refrigerant level issue.

Are you looking to do this yourself?

 

[graciebrother]

I think my main goal here is to try and determine that the sounds isnt going to affect anything else. If I can find out what it is, if basic then I could do it myself. If not then I can take it to get repaired. It's not affecting the car at the moment, it's just something I want to iron out. But I'd been keen not to drop $500 doing so being a 98.

I understand that it's difficult to pinpoint the problem when you can't see it/hear it for yourself.

 

[KPT]

Does the noise occur in heat or vent mode? I'm thinking it might be the blower motor.

 

[graciebrother]

Hi,

The noise only occurs when in either of the a/c modes. Normal running of the blower is fine even on the highest setting.

 

[bluestream1]

Does it sound like it is coming from the compressor? can you hear the noise when looking with the hood up? I would get it looked at; compressor may just need some oil.

Unfortunately, you can't buy R134a in Canada unless you are a licensed refrigeration technician

 

[graciebrother]

Is the compressor the black unit coated in foam? If so, there doesnt appear to be any noise coming from there. From under the hood it's more of a whirling groan from either of the front two units. It's hard to tell which really. Neither is vibrating more than the other to give away any clues. I just ran the engine and turn the a/c on max and it's nice and cold in no time.

 

[RockyMtnHigh]

A Rocky Mountain hello to Graciebrother on the coast in beautiful Vancouver.

Max A/C does not provide any more A/C power. It recirculates the existing air, not drawing any warm fresh air from the outside. Use it when your truck has been sitting in the sun and you want to cool it quickly, then change to A/C so that you are getting fresh air intake. Max A/C makes much more fan or blower noise than A/C. This is normal as the system is closed to the outside.

What happens to the sound if you change the temperature setting while running A/C? Try it at full cold, the middle and full hot. Try doing this with the truck at normal operating temperature.

 

[robertoa1a]

Ya' still need tools!

 

[robertoa1a]

And with a halogen detector and thermometers you can start. Or you can ps-in' the wind! At nine bucks a 12 oz can you can do $100 worth of experimentation then think you found a leak and do it again or just sed it to a shop. If yopu replace anything you will have air in the system. Then you use a vacuum pump prior to recharging the system if you do it right. That is a lot of tools, isnt it.

This is not one for the light harted shade tree mechanic in my opinion.