okay! ive had a thread before about the a/c system! this is something ive been trying to figure out! ive done some guess work, but anyone with better ideas, or even things to look at would be great! yes the a/c doesnt work all that great still, even after evactuating it and replacing the comrpessor, etc. and im not too worried about it right now since its cold and almost winter, cept for maybe defrost.

well for a long time it made some squaky noise when running, but i think i fixed that by spraying some belt dressing on the drivebelt. its pretty quiet now.

there is one thing im concerned about and im only guessing at possibilites.

it makes a loud grind noise (like when you start the car while its running) and it really sounds like its from the compressor not the starter... it does it after it has been sitting a long while.. i dont think the outside temp matters.

so i unplugged the a/c switch that is right before the condensor (low/high side cant remmeber which line), but i think the camry only has 1 anyhow. well from the few days ive tested it, i dont recall hearing it. so i plugged it in recently and it does it.. little quieter, but still does it then goes away. i can turn off the car and turn it back on and i dont recall hearing it doing it. only when its been sitting .. almost (but maybe not always) every time. i can turn the a/c on and off in the car on the climate and hear the compressor kick on and off but not remake the sound.

one day i had my GF open the hood, and i looked under it with a flashlight right before she started it, but of course it didnt do it that day! .

im wondering if the a/c is trying to engage as i start the car and for some reason the car doesnt like it. or its not disengaging when i turn it off. (whether i had it on or off already before i turned it off)...

would it be a relay, or this switch by the compressor? is it detecting some sort of pressure so the switch freak out,. or maybe its nothing... a problem with the compressor? a problem with the compressor speed sensor on the bottom which i cant find much info about if it would cause a problem but i know what it suppose to do... or maybe not the compressor at all! but i really dont think its the starter......

and i dont recall it ever doing this on the original a/c pump that made a lot of noise, when engaged or disengaged... only on the ones i replaced it with.. so i dont know what to do! i rather do what i can do, before i dish out too much money for this... next year..

 

i just did an experiment. the car prob. sat for abour an hour.. maybe... i went out there, unplugged the a/c switch by the condensor. and started it. it started fine. no grind noise , jsut idle high cuz its been sitting in the cold.. then i turned it off and back on and still no noise... i made sure the climate control was off, everything... i turned it off . went back out and plugged the switch in , and turned it on.. made a slight grind then it went away... turned it off, back on. did it again. usually it only makes it once then it stays away until it sits.....

so it has to be the compressor. by why is it when the switch is plugged in and only when the car is started. . i can turn the compressor on and off afterwards and no new noise. even turn the car off and on and no new noise. only when i start it after its been sitting... except this time, it usually only does it once... until it sits again

is it the switch, and why would it be? i thought it was to turn the compressor off when the pressure was too low or high... just things to consider

 

Why was the compressor replaced and who did the work?

The compressor will only engage if the AC system is on and even when on the compressor will cycle on and off.

The compressor has a magnetic clutch that engages the drive pulley. Find the wire to the clutch and disconnect it. Then do your tests as before and determine if the compressor is still making the same noise. If so the problem could be the magnetic clutch.

When the clutch wire is connected and AC on, watch the compressor as it cycles on and off. The engine RPM will lower slightly then pickup when compressor starts up. Determine if the noise starts and stops with the compressor engaging.

 

well, it's not the compressor. those are quite tough to break. it's your compressor clutch.
1. beltease or equivalent is only a temp fix, belt needs to be replaced
2. clutch belt pulley and magnetic system with friction plates, that engage when current runs through coils. also, some sort of dampener, similar to one in clutch plate. normally, pulley spins along with engine, but when magnets fire, it is caught by plates and turned, engaging clutch. the outside plate can go bad, had 2 of those happen. also, pulley bearing goes bad, had that happen twice too.
most likely, noise you hearing is plate skipping on it's counterpart. might be bad magnetic coil. happens.
btw, you better off disconnecting clutch from plug on it, or simply pulling a/c fuse out.
I do not anvy you. no one wants to sell you parts for clutch, they all want to sell you entire assembly. if it's bearing, and it CAN BE VERY LOUD, it can be replaced, but clutch has to be removed, bearing pressed out (hammer and socket) and matched at a store. I was blessed having O'Reily's guys in Hermitage, TN, who were dogs on doing this. Bless their hearts, they saved me ton of $$.

 

okay. it only does this when the car is started after sitting, afterwards, i can turn turn the a/c on and off and i can hear the compressor kick on, and even go out and look at and its spinning. it isnt cycling! but it only does this when the car is first started, and the a/c should be off.... i dont get any other bearing sounding noise anymore or anything, since i sprayed on the belt , and i can replace it. i was reading some thread somewhere, so i was curious if the belt was any cause. wasnt expecting a cheap fix (tho it would be nice) the belt isnt that much, but it was more to see if the belt had anything to do with it.

now the grinding noise that you hear like when you try to start the car after it is already started is still there. .. it goes away when you unplug the cycle switch, why i dont know, when you plug it in, it came right back! .... now i had the car sit for a while, then i didnt try to start it until i unplugged the cycle switch, well it didnt make the noise, then i turned it off and back on .no problem. but then i turned it off, plugged it back on, turned it on then first thing it made the noise.. after that i can cycle it on and off no problem! i know the noise it makes, normally, plus the engine idle change noise..

the original one. made a lot of noise.. first while it was running, which went away when yhou turned it off, then it made it constant... we drove it all winter into the spring before i attempted to replace it... i kept the original one, until the a/c problem is totally fixed. you can spin the pulley wheel on it and tell it makes noise... well i replaced it with supposedly a oem new /not rebuilt one. charged with oil.. i had it evacuated at my uncles (who has all the equipment) and vacuumed, replice the drier and put it on.... , charge it, flushed it, etc. and now this.

it doesnt make any noise now, cept when you start the car (a/c suppose to be off), after sitting for a short time..

i can go out right now and unplug the 3-wire plug by the compressor and start it and see if it makes noise, then plug it in and see if it does. then ill come back and update

 

well i unplugged it and it started with no noise, i plugged it in and it made a little noise and stopped. but then it wouldnt turn on or off.... . now its cycling , i hooked the freon gauge up to it and the freon is very low.. whih was filled, even with stop leak (which i know its considered evil), so apaprently that didnt work, even with dye . didnt see an external leaks.. unless its from the inside... it hasnt cycled until now that i unplugged it down there and re connected. before it turn on and off just fine.. so i dunno maybe it didnt realize it was low on freon like it should.. so i will get a can charge it a little and see if it clears it up for a while. if not. i dunno.. i guess ill have to leave it unplug and fix it next year when i can afford to have it in a shop..

 

Belts can cause strange noises as if a bearing is squeaking. If carefully you can move the belt with a bar with engine running and determine if the sound goes away or changes.

If the Freon is too low the compressor will be locked out do a a pressure switch and not operate. However before it reaches this state the low Freon will be hard on the compressor.

The magnetic clutch should be off when the AC is off. Use a volt meter to determine if power is available at the wire going to the clutch and chassis ground when the AC is off. The should be no power when the AC is set to off.

 

whatever belt noise i could have heard before, went away with the belt dressing spray. of course i intended to replace both the drive belts, just wanted a quick probably harmless test.... didnt have the money at that moment to get the belts, but i can before winter... i hooked my gauge up to the low port when i turned iton... for some odd reason the compressor.. turns off and on now (the last attempt i made to check it out).. it didnt do that all this time.. so i hooked the gauge up. when the clutch isnt engaged. the psi was between 30-40 (i noticed it wasnt spinning), then it clicked on and it dropped to the white part , but not bottom out.... so i dunno i can add a little freon just so it doesnt run low until i figure out what to do to have it fixed right..

now i can test the wires tomorrow in the daylight for voltage..... to the clutch when the a/c is off. but the car isnt started... now just an idea, if theres voltage to it. with the ignitino on (not started), but the a/c off... what would cause that?..

 

clutch is supposed to cycle on and off.
Asian makes have climate controls set so that a/c turns on every time your air flow choice is set to windows defrost/defog. been like this for years.

 

oh, and do not add freon only. add freon/oil mix, or you will seize compressor. also, what will happen, by recharging system, you will create more resistance to the belt. and engine.