A/C Compressor kicks on and off, on and off - AC Clutch?? IT's HOT here!

ogboot · 06-17-2009, 02:17 PM

So i got my car back from the shop on an unrelated issue to this, and they told me that my AC was acting up but to drive it a little bit as it may just be an issue with the car sitting up for a while that would work itself out.

Here goes:
Turn on the A/C when the car is cold and it will work fine for about 10min. then it starts "knocking"... about every 5 seconds it makes this *tock* and the AC compressor stops, then it gets going again for a few seconds and *tocks* to a stop all over again.

This happens at idle and cruise. I've been told this could be from low freon, but the shop said they checked the freon level and it was good.

Some possibilities:
1) They don't know what they're talking about and it really is low on freon/leaking.
2) A/C Clutch acting up.
3) Random TSB i found on here from searching that exhibits this behavior because of a faulty sensor in the A/C system that misreports system freezing up.
4) A/C system actually freezing up.
5) compressor dying and i should drive car off of a cliff.

I'm going to dig around for my pressure gauge to check the A/C system when i get home from work, can anyone offer some input? Thanks.

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crampfan · 06-17-2009, 03:04 PM

yep, the best thing to do is hook up the gauges. could be a low charge, over charge, or electrical.

jay25RS · 06-17-2009, 03:33 PM

I had a similar problem... ended up being overfilled... but in your case if no one touched the refrigerant lately, then I vote for...

3) Random TSB i found on here from searching that exhibits this behavior because of a faulty sensor in the A/C system that misreports system freezing up.

Mulder · 06-17-2009, 03:46 PM

This is not the freeze-up issue. That will only happen when the system has been running for a while, and when it does the compressor will keep running but airflow through the vents will decrease and may stop.
What you're describing here sounds to me like an overcharge condition. When the compressor cuts out from the high-pressure switch it will be more violent than its normal cycling.

ogboot · 06-18-2009, 04:40 PM

unfortunately i couldn't find my A/C kit so i'm going to have to check and see if Autozone or somebody can at least check the pressure for me when i get off work. doh.

ogboot · 06-18-2009, 08:38 PM

went and bought another guage, it was only about $20. What do you know, overfilled. Mulder hit it on the head. "Somehow" lost about 5psi of freon and everything is fine so far now.

wagonovsky · 06-18-2009, 11:04 PM

Somewhere the penguins are crying.

Quote:

Originally Posted by ogboot

went and bought another guage, it was only about $20. What do you know, overfilled. Mulder hit it on the head. "Somehow" lost about 5psi of freon and everything is fine so far now.

ogboot · 06-19-2009, 12:00 AM

Quote:

Originally Posted by wagonovsky

Somewhere the penguins are crying.

Let's soak up some A/C and have a moment of silence for the penguins...

ok i'm good now.

MAJRMSA · 06-19-2009, 10:34 PM

I have a similar situation after having the a/c system charged twice again this summer. The first time I had the famous leak at the high pressure hose and now the a/c clutch on my compressor seizes at random times. I get a sort of violent jerk in the car and a quite a loud thump as well. I opened the hood and noticed the a/c clutch was not spinning normal but rather going back and forth as if it was stuck and making the whole compressor jump. I take the car in it to the shop tomorrow so they can check it out. But does this sound from an overcharge condition? Is my compressor going again? I replaced it once already. As these bugeyes age it seems as if though they are plauged with a/c issues.

ogboot · 06-20-2009, 11:18 AM

i didn't have any issues at all until they overfilled mine (engine swap). what i noticed is that in the morning and evening (when it was cooler) the A/C was fine, probably because it was lower pressure at those times. However, once the temp rose in the middle of the day and the afternoon I would start having issues, because this would also cause the pressure in the system to be higher. So, in a way I can't completely blame the shop for overfilling it because they charged it in the morning and it was probably ok at that time.

Check out my first post, i've had squeals before from belts but this was quite a thump, and as you mentioned the car would stumble. Good luck with your issue!

06-17-2009, 02:17 PM	#1
ogboot Scooby Specialist Member#: 170906 Join Date: Feb 2008 Chapter/Region: South East Vehicle: 2002 WRX psm	A/C Compressor kicks on and off, on and off - AC Clutch?? IT's HOT here! So i got my car back from the shop on an unrelated issue to this, and they told me that my AC was acting up but to drive it a little bit as it may just be an issue with the car sitting up for a while that would work itself out. Here goes: Turn on the A/C when the car is cold and it will work fine for about 10min. then it starts "knocking"... about every 5 seconds it makes this tock and the AC compressor stops, then it gets going again for a few seconds and tocks to a stop all over again. This happens at idle and cruise. I've been told this could be from low freon, but the shop said they checked the freon level and it was good. Some possibilities: 1) They don't know what they're talking about and it really is low on freon/leaking. 2) A/C Clutch acting up. 3) Random TSB i found on here from searching that exhibits this behavior because of a faulty sensor in the A/C system that misreports system freezing up. 4) A/C system actually freezing up. 5) compressor dying and i should drive car off of a cliff. I'm going to dig around for my pressure gauge to check the A/C system when i get home from work, can anyone offer some input? Thanks. * Registered users of the site do not see these ads.

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06-17-2009, 03:04 PM	#2
crampfan Scooby Specialist Member#: 74321 Join Date: Nov 2004 Chapter/Region: MWSOC Location: clarksville AR Vehicle: 2004 wrx wag black UTEC stg 4	yep, the best thing to do is hook up the gauges. could be a low charge, over charge, or electrical.

06-17-2009, 03:33 PM	#3
jay25RS Scooby Specialist Member#: 4273 Join Date: Feb 2001 Chapter/Region: NESIC Location: CT Vehicle: 2011 GR-STI & 2013 Impreza Sport	I had a similar problem... ended up being overfilled... but in your case if no one touched the refrigerant lately, then I vote for... 3) Random TSB i found on here from searching that exhibits this behavior because of a faulty sensor in the A/C system that misreports system freezing up.

06-17-2009, 03:46 PM	#4
Mulder Trust no one Moderator Member#: 11170 Join Date: Oct 2001 Chapter/Region: Tri-State Location: NYC Vehicle: 02 WRX 05 GTO/11 Sonata(!)	This is not the freeze-up issue. That will only happen when the system has been running for a while, and when it does the compressor will keep running but airflow through the vents will decrease and may stop. What you're describing here sounds to me like an overcharge condition. When the compressor cuts out from the high-pressure switch it will be more violent than its normal cycling.

06-18-2009, 04:40 PM	#5
ogboot Scooby Specialist Member#: 170906 Join Date: Feb 2008 Chapter/Region: South East Vehicle: 2002 WRX psm	unfortunately i couldn't find my A/C kit so i'm going to have to check and see if Autozone or somebody can at least check the pressure for me when i get off work. doh.

06-18-2009, 08:38 PM	#6
ogboot Scooby Specialist Member#: 170906 Join Date: Feb 2008 Chapter/Region: South East Vehicle: 2002 WRX psm	went and bought another guage, it was only about $20. What do you know, overfilled. Mulder hit it on the head. "Somehow" lost about 5psi of freon and everything is fine so far now.

06-19-2009, 10:34 PM	#9
MAJRMSA Scooby Newbie Member#: 22399 Join Date: Aug 2002 Location: Houston, TX Vehicle: 2002 wrx 200k mile high club	I have a similar situation after having the a/c system charged twice again this summer. The first time I had the famous leak at the high pressure hose and now the a/c clutch on my compressor seizes at random times. I get a sort of violent jerk in the car and a quite a loud thump as well. I opened the hood and noticed the a/c clutch was not spinning normal but rather going back and forth as if it was stuck and making the whole compressor jump. I take the car in it to the shop tomorrow so they can check it out. But does this sound from an overcharge condition? Is my compressor going again? I replaced it once already. As these bugeyes age it seems as if though they are plauged with a/c issues.

06-20-2009, 11:18 AM	#10
ogboot Scooby Specialist Member#: 170906 Join Date: Feb 2008 Chapter/Region: South East Vehicle: 2002 WRX psm	i didn't have any issues at all until they overfilled mine (engine swap). what i noticed is that in the morning and evening (when it was cooler) the A/C was fine, probably because it was lower pressure at those times. However, once the temp rose in the middle of the day and the afternoon I would start having issues, because this would also cause the pressure in the system to be higher. So, in a way I can't completely blame the shop for overfilling it because they charged it in the morning and it was probably ok at that time. Check out my first post, i've had squeals before from belts but this was quite a thump, and as you mentioned the car would stumble. Good luck with your issue!