jeda_zelda

As Winter broke and Spring approached, I noticed that as I turned the climate control dial down, I was not getting progressively cooler air unless I turned it all the way to "60".

So, now that the summer heat has set in, we've started noticing that in the morning the A/C is cold - period. Then on the ride home, it's intermittant at speed/RPM and totally nothing at idle but will come back on, cold, when speed resumes.

So, I have the car at a shop to have it checked out....anyone want to take a guess at what it'll be?

jeda_zelda

Well...shop just called. They're saying the serpentine belt looks original as it was dry cracked and stretched (125kmi). They replaced it and drove the car...air was totally cold. We'll see tomorrow on the ride home after it's sat in the sun and heat all day and has to make cold air for an hour in bumper-to-bumper stop-and-go traffic...that'll be the real test.

Gingerbreadman

you sure didnt give us long to guess! i am gonna go out on a limb and say I bet they didnt fix it though. I bet it is low refrigerant. The reason i say this is the a/c kicks on when you get below the desired temperature in the car and runs full power until the interior temperature reaches the desired points. The blower may blow harder or the auto controls may mix some heat into the equation to keep you from getting frozen to death but the a/c compressor/internals do not run at higher powers the colder you set the dial... only longer.

I could be wrong about this in some cases but on a side note my wife drives me CRAZY with this issue. She will set the A/C in the house on like 50 degrees if she is hot, thinking that the house will cool down faster if she does so. Then she forgets to set it back and i wake up with icecicles on my nose and steam spewing forth at every breath (obviously a bit of an exaggeration).

I am guessing that the outside temperature has something to do with the expansion /shrinking of the refrigerant and puts you over and under the amount you need for it to function properly.

We'll see tomorrow. Let us know.

Gingerbreadman

jeda_zelda

Gingerbreadman...your partly right...they didn't fix the whole problem.

On Wednesday evening the a/c basically quit all together, although it started to blow cold air a couple times on the commute home but then it would go back to warm air all together. Now, I'm back to an a/c that works but one that's totally RPM dependent.

My deductive reasoning tells me a few things....
1. The shop I took it to sucks cause they obviously didn't test the a/c system before and after they decided that it was jsut the serpentine belt...real good guys, thanks!
2. The amount that the A/C works, shouldn't be RPM specific...at least that's not what I remember when the car was new.
3. If the engine RPM is what's driving the A/C compressor (ALA the serpentine belt)......ahhhh, could it possibly be that the compressor isn't engaging on it's own like maybe it should???

I have no idea what the real process that the A/C system works by, but I imagine that the compressor should engage/disengage regardless of RPM... ? So if anyone is a real techie about the a/c system...please educate me, I'd love to hear how it's suppossed to work under normal operating conditions.

Thanks, Bill

whatwasthat

well, to know if your compressor is working, turn the a/c button on and off, and you should hear a clicking/clunk noise along w/ it. ... and yes, it should engage/disengage regardless of RPM

jeda_zelda

whatwasthat......I'll try that this afternoon, but is the compressor an all or nothing kinda thing? Like, does it work or not work?

I drove past the shop that did the work to tell them that what they did, didn't really resolve the problem. They asked to have the car back so they could measure the amount of pressure in the system as the shop owner thought that it was probably low. I'd buy that if it just took a long time to get cold, but not when it goes cold when at sustained rpm's and then warm when in stop-n-go or a stand still....

Gingerbreadman

The compressor is powered by the revolution of the cars engine. The power is transfered from the crank to the compressor via the serpentine belt the same way that the alternator gets it's power.... Obviously the engine will turn at different speeds and the compressors needs will be different and not necessarily in synch with the engine speed. By this I mean that you may be at idle, slow engine speed, and have just started the car on a hot day, high compressor need. To allow for this the compressor runs on a centrifugal clutch allowing for changes in compressor speed independant of engine speed.

Now if you think about that for a second and how centrifugal clutches work then the rpms of the engine should not have much effect on the cooling capacity of the a/c. It does have a little, especially as the clutch gets more used, but it should not be an off and on type deal dependant on rpms.

You should have let them check the pressure/refrigerant of the system or you should check it yourself. I am writing in at least 2 threeads telling people to check there refrigerant.... it takes like 5 minutes and 35 dollars and is about 85% of the time gonna fix the problem but no one has tryed it yet. Just try it or let the guy who didnt fix it the forst time do it if he is gonna do it free since he fixed some shit hat won't broke the first time.

jeda_zelda

Well....shop reports that the system was more than 1/4lb low on R134. Anyone know what the correct pressure for the system is and if that's enough to make the system be affected in late afternoon temps?

Gingerbreadman

As far as is the compressor working.. the things i have seen go wrong with that are the clutch and the bearings in the pulleys, both make a hellish noise and can even cause the pulley to lock up which will freeze it in place... rub the serpentine belt over it, creating a hell of a screaming noise, and burning a the belt in two.

The little pistons that compress the refrigerant may wear but that would only cause them to work a little less efficiently and probably not cause the unit to fail, imho. somene else may know more about this as i am in no way an expert and am merely stating things as I understand them to work. I believe most of my facts are correct but then we all do until we are shown to be wrong don't we.

Gingerbreadman

the pressure and the amount of refrigerant are different. the pressure is dependant on the amount of refrigerant but still they are different. I believe the pressure on the low pressure line should be like 25-45 lbs. i would have to look at my gadge to be sure as it is color coded to proper pressures. The total amount of refrigerant in the system is probably like 3 lbs or so, but that is a refrigerant/oil mixture. I would be surprised if the 1/4 lb was all that the system was low. A can at the car parts store is like 16-18 oz (1 lb) and I would guess a can would be the least to make a significant difference. I mean that he may have put enough in to get you back working... but if you have a small leak (which as I have said before most systems do at least a little) then you will be right back in the same boat soon.

Good luck, and I hope at least some of my babbling helps.

jeda_zelda

Thanks for replying again G-man.

The true test will of course be tomorrow's commute home. The shop owner pulled this same crap last week telling me it was just the belt and that they tested it and all was better. I keep telling him that it works anytime of day except in the late afternoon heat...then it only works with sustained RPM's. Next stop is the Stealership cause I'm getting sick of this.

Will report tomorrow or Wednesday.

jeda_zelda

Well...seems my trusty shop is determined the compressor is bad...Certianly makes me wonder why they didn't look a little closer at the compressor last week the first time I brought the car in!!!! Anyone know the going rate on an OEM replacement?

jeda_zelda

well...nothing's any better....first it was the compressor & now a second shop that speciallizes in a/c replaced the "accumulator" as it was restricted......So $1k later...still the smae problem!!!!! Everyone think these guys really don't know what they're doing???? :rippedoff

fsttyms1

back to one of the other posters coment, do you hear or feal the compressor kicking in? if not it may be in the HVAC controls. when its not working right listen and feel for the compressor surge. a bad hvac contorller could be sending the wrong temp control and not allowing it to cool to makx potential. ths is why 9x out of 10 the dealer should be where you bring the car, they have the car specific tools and technicians that (in most cases) have seen the problem before and know what to fix the first time

Gingerbreadman

jeda-zelda,
at this point i believe the best advice you can get is to push back on the shops that you have spent money with so far. You, in good faith, spent money with them to correct things that they said were causing your problem. It in fact did not correct the problem at all. I would push back on the shop and tell them that obviously they had fixed the wrong thing and i would express the doubt that what they replaced was ever broken to start with. I would in no uncertain terms tell them what I expected of them to rectify this situation which would be at a minimum to find and correct the actual problem and at no cost to you unless they could show you that the actual problem would have been more expensive than the "supposed problem" that you paid for. Acftually I would probably demand they fix it free and only allow the "pay the difference option" if they insisted.

A perfectly understandable reaction would be to get frustrated with the shops you have been to and to write them off as unknowledgable about the problems you are having. People are just people and regardless if you go to the dealership or to bill the mechanic up the road they will sometimes make mistakes. Hopefully less at the dealership since they tend to work on your exact car more so than on all cars but that advantage comes at a premium price. I tend to use the smaller mechanic as well, both because it gives the small man a chance and because it tends to be cheaper for me in the long run.

The shop you took it to should be able to eventually fix the problem... either that or they should (and I stress should) offer to pay you back your money and take the loss. It may involve item by item replacement of your whole cooling system and may take a lot of patience on your part but since you already have the money spent I would go that route.

Good Luck.

optomos

Are you keeping the system in "recirculate" mode? The button of a car that is in the center. I know when my system is in auto mode sometimes the computer for some unknown reason will turn that off & start letting the hot air from outside in. Also have you replaced the cabin filter since you have owned the car?

JMAL

Sorry to drag this up, but this is the only thread with the exact issue i am having.

03 tls 82k. AC works when driving for the most part. When running is cold. however when i wait at a light or at idle it clicks off. When in idle the compressor clicks on for a second there is a put put put from the intake and rough idle then the compressor clicks off. does this a few times then gives up.

Any ideas or resolution from anyone else? Is it low on refrigerant? Compressor bad? Sensor?

Like i said above, when it works, its fine. i dunno what to do. help

MotionEffects

is your radiator fan working?

JMAL

Yeah, when i start the car and turn the AC on it runs (compressor and fans) for about 8 seconds then turns off for about 20 seconds then back on for 8 or so. this repeats until the motor sputters when the ac compressor kicks on this is about 3-5 mins into the idling. There is a hickuping from the engine intake a few times then it turns off the compressor, but it repeats more quickly when the hickuping happens.

but when i am driving it stays pretty cold. When i sit at a light is clicks off. the line that runs by the power steering pump is ice cold when the compressor is running. the blower motor is fine, the fans run, compressor works when engaged.

I have founds so many similar threads but no one ever has a clear resolution.

MotionEffects

from your description, there seems to be 2 problems. 1. The fan is working but is sucking strong enough to cool the condenser? When the vehicle is moving, the air pushing thru the condensor is strong enough too cool it down, hence your getting cold air while driving. 2.the rapid on/off compressor is from low freon.(if your freon is low, there is a leak in the ac system).

finalcross

iTrader: (3)

My A/C was squealing every time that I turned it on and when I turned it off the noise would go away but I felt the cold air. I just got my tension belt replaced today and now the A/C works perfectly but you have more of a climate control problem.

JMAL

So i should get a leak down test? The fans are running full force, do you think the running ac while driving might be an rpm+compressor relation?

jdjohn84

The compressor will cycle on-and-off more frequently when the pressure (and freon) is low. You need to check the pressure (low side) in order to confirm that the freon is low; pressure should be 35-40psi to operate normally. And, due to low freon and frequent on-and-off cycling, it will not cool as effectively. You may only have a slow leak and just need topping off of freon, so I wouldn't get a leak test done just yet.

Your engine should increase RPMs when you press the AUTO button for a/c, even if the compressor is not working correctly. It does this in anticipation of the compressor clutch engaging, whether the clutch engages or not. If the RPM increase is not happening, you may have another issue as well.

JMAL

Just to narrow this down, it does boost or surge the rpm when the compressor turns on. im going to try and get a pressure test done this weekend. so if the freon is low, then its safe to assume there is a leak somewhere.

MotionEffects

Have the pressure checked. Low side should be anywhere from 29psi to 35psi and high side should be around 2.5x the ambient temp. i dont know if its worth your while to take a trip to where i work in south jersey and i can check it out.

jdjohn84

You could test it yourself. They sell gauges and even charge kits with gauges included at parts stores. Yes, there could be a leak, but it could be very small such that you will just need to give it a charge boost once a season. That's not bad. It may have been leaking a little over a long period of time, and now you need your first recharge.

JMAL

yeah that is true, it could be a super slow leak.

Motion: thanks for the offer, if i cant get anything resolved here i might take you up on that. plus i need new inner tie rods so im not road tripping till i get those in too.... when it rains it pours. car was no worries until now, AC issue, tie rods, headlight flicker....

friesm2000

iTrader: (4)

just a FYI for people calling it freon, it is actually called refrigerant (Freon is a trademarked name for Dupont, like Kleenex), and more specifically it is R-134a refrigerant

jdjohn84

Yeah, I know, but I'm old. R-12 is the old stuff. Or some people just call it 'gas', but that might be even more confusing.

friesm2000

iTrader: (4)

i was not even 8 when that crap was phased out in 94 LOL