Loud click noise when AC is on

[Putzo]

I have a 2014 sonic LT turbo 6 speed manual. It has 34k miles on it. One thing I have noticed is when the air conditioning is on I hear a loud click/clunk noise from the passenger side engine bay every 15-20 seconds or so. The air conditioning works fine, but it just seems odd to me. Is this normal?

Another issue is when the AC is on there is a intermittent hissing noise coming from the engine, and occasionally a squeel/squeek, but it doesn't sound like a loose belt. I've seen other people post about this as well, is it a problem?

I figured I would ask here first before taking it in to the shop because if its normal I don't want to waste my time. Thanks for any help.

 

[Natesriv]

The click is probably the compressor clutch engaging.

 

[Putzo]

The click is probably the compressor clutch engaging.

Is it normal for it to click on and off so frequently? I would think it would only engage/disengage when I turn the ac on or off, or press the snowflake button on the dash to turn on the compressor. It seems strange it would be constantly turning on and off.

 

[UltimaSanctus]

Is it normal for it to click on and off so frequently? I would think it would only engage/disengage when I turn the ac on or off, or press the snowflake button on the dash to turn on the compressor. It seems strange it would be constantly turning on and off.

It clicks on and off because the compressor builds up pressure then when its done it disengages the clutch. The pressure slowly goes down (hence the hissing) to a point where the computer tells the A/C clutch to re-engage and the cycle repeats itself.

 

[Putzo]

I ended up taking it into the dealer to get it looked at since I am about to hit 36k miles and one of my warranties is about to run out. Turns out a hose from the compressor to the condenser was leaking so they replaced that and recharged the system. When I dropped the car off the service guy told me it sounded like there was a low charge and thats why the compressor was engaging and disengaging so much.

This is probably unrelated to the problem but they also replaced the battery. Both were covered under warranty.

I after this and a loose door striker that was fixed a few weeks ago I am little concerned with what else will pop up on this car, especially since the 36k warranty is about to run out. In the mean time it sure is nice to just drop off the car and let the dealership take care of it, I'm used to spending hours diagnosing issues and busting my knuckles on weekends to get my car back on the road.

 

[Natesriv]

Glad its fixed

 

[Italianjoe1]

Mine does that and the system isn't low on charge. The compressor just cycles a lot when you're running the a/c at low speed, the compressor pumps until the evaporator is at freezing temps, then shuts down until the temperature rises 6-8 degrees. Then back on. Keeps the evap from icing up.

 

[SuperFudd]

I have never heard it on this car.

 

[Putzo]

I seem to still hear a strange kind of hissing noise periodically, but the compressor is definitely cycling less.

 

[Italianjoe1]

I have never heard it on this car.

Doesn't seem as noticeable in the 1.8l cars.

 

[jyahknots]

I have a 2015 LT with the 1.4 in it, but mine is an automatic (not that any of that makes a difference). I hear the VERY LOUD clicking (compressor clutch engaging) quite a bit. What strikes me as odd, is how LOUD it is when it engages and disengages. I brought it up to my dealer the first time I brought it in for service, and they told me the found metal shavings inside the compressor, and ended up rebuilding the compressor. They evacuated the system, checked it for vacuum leaks, then refilled it. They said that what they did should fix the issue......but it didn't. Still hear what I feel is a very loud a/c compressor. Every time I take it in now I bring up the issue, and it's always, "Ahh, that's normal. Don't worry about it." It's so loud that when I'm parked in a parking lot and the a/c is running, it scares people walking by! But hey, "It's normal!"

 

[Putzo]

I have a 2015 LT with the 1.4 in it, but mine is an automatic (not that any of that makes a difference). I hear the VERY LOUD clicking (compressor clutch engaging) quite a bit. What strikes me as odd, is how LOUD it is when it engages and disengages. I brought it up to my dealer the first time I brought it in for service, and they told me the found metal shavings inside the compressor, and ended up rebuilding the compressor. They evacuated the system, checked it for vacuum leaks, then refilled it. They said that what they did should fix the issue......but it didn't. Still hear what I feel is a very loud a/c compressor. Every time I take it in now I bring up the issue, and it's always, "Ahh, that's normal. Don't worry about it." It's so loud that when I'm parked in a parking lot and the a/c is running, it scares people walking by! But hey, "It's normal!"

I brought my car back in as the noise has persisted and the clutch still seems to disengage and re engage quite a bit. Also, the noise from engaging and disengaging seems to have gotten louder. I agree, it is odd how LOUD the engagement is on my car as well. Cars make noise, but it just doesn't seem right. I will probably take it back this weekend.

 

[jyahknots]

Their Response?

I brought my car back in as the noise has persisted and the clutch still seems to disengage and re engage quite a bit. Also, the noise from engaging and disengaging seems to have gotten louder. I agree, it is odd how LOUD the engagement is on my car as well. Cars make noise, but it just doesn't seem right. I will probably take it back this weekend.

What did they tell you when you brought it in? And let me know what they tell you after your weekend visit.

 

[Putzo]

What did they tell you when you brought it in? And let me know what they tell you after your weekend visit.

I brought it back a few weekends ago but they were too busy to look at it. I will be taking it back again this weekend. I will let you know.

 

[Putzo]

What did they tell you when you brought it in? And let me know what they tell you after your weekend visit.

They looked at it again and replaced the evaporator temperature sensor because of a technical service bulletin. It still makes the noise occasionally, seems like less than before, but now that its cooler here I really don't use the AC much now. I guess the air conditioning just makes that noise. The A/C functions fine so it is what it is. I'm done worrying about it.

 

[jyahknots]

They looked at it again and replaced the evaporator temperature sensor because of a technical service bulletin. It still makes the noise occasionally, seems like less than before, but now that its cooler here I really don't use the AC much now. I guess the air conditioning just makes that noise. The A/C functions fine so it is what it is. I'm done worrying about it.

Gotcha. When I take mine back in, I'll ask about the temp sensor too. Thanks for the heads up.