A/C compressor/clutch vibrates at idle.

[ajkalian]

2000 Camry LE, 1MZ-FE, 230,000 miles

Recently I've noticed that when I come to a stop and the engine idles there is a noticeable shaking coming from the engine compartment. I lifted the hood and it got worse when the fans cycled on with the Air Conditioner, so I thought that maybe that one or both of the fans were on their way out.

I did a bit of research about the radiator fans, and found out some confusing info. More on that later. I figured that the best way to test the fans, would be to remove them one by one, put them on the ground, connect a 12v power source and see if they spun or vibrated. They were easy to remove. The one on the right (PS) has three bolts holding it in place, two one the top, one on the bottom. It is necessary to drain a bit of fluid from the cooling system to get the level below the top radiator hose, since it must be moved out of the way to allow for the fan to be removed. The fan on the left (DS) has two bolts on the top and two pegs on the bottom, and it removes easily. I found that if I removed the skid plate from the front of the car under the radiator, it makes it much easier to get to the bottom bolt that held in the PS fan from the bottom, rather than the top. And it made draining the coolant a bit easier too. Didn't spill a drop.

Why they didn't make the fans identical and the mounting arrangement identical is anybody's guess. When I first thought it was the fans I did a bit of research into what it would cost to replace one or both of them if they turned out to be out of balance or had bad bearings.

It turns out that the fans are not radiator fans. Well, that's not entirely true. I checked the part numbers at Rock Auto and ran into some problems locating both of the fans. I found the one part #16363-0A050 in the radiator area but couldn't find any mention of the other one. I called tech support and the guy explained it. The fan on the left (Driver Side) is the radiator fan; the one on the right (Passenger Side) is called the compressor fan. If you look for the compressor fan in the cooling system area you won't find it. You have to go to the Air Conditioning area to find the compressor fan, and as you probably imagine, the radiator fan isn't listed in the Air Conditioning area. And sure enough when I checked, that's how it was listed. The Rock Auto tech support knew right away what the problem, and knew right away where the correct part was. I can only wish all tech support people were that on the ball. Anyway I put something together that explains what is where in case anybody needs the info. Both OEM and Dorman part numbers are listed.





With both the fans on the floor I plugged them into a 12v source. They started right up and ran very smoothly. Not a bit of vibration. Both of the fans were good. So that was good news, and I put them back and topped off the coolant. I could have just as easily unplugged each of the fans one by one and tested them in the car, but I wanted to be able to get a good look at them to check for cracks in the housing, etc. Now it was time to concentrate on the A/C compressor and the A/C clutch. I removed the A/C belt and started the car. No vibrations at all, so it was the A/C compressor or the clutch.

I took a look at where the A/C compressor was and it was under the alternator. It wouldn't be that hard to remove the alternator. But then I noticed that the A/C compressor clutch was about 1/2" from the fender.
No way to fit any wrench in there to get the clutch off. And I also didn't see any way once the alternator was removed to un-bolt the A/C compressor and wiggle it free to get it in such a position to remove the clutch. So that would mean that I would have to take it somewhere and pay to have the R134a removed, then unbolt the hoses, and remove the A/C compressor, to replace the clutch, and then back to the A/c shop to have it evacuated, oil added, and re-charged. Then if the rumble was still there, then I'd have to do it all over again, only this time I would have to replace the compressor, and fill with new oil, and R134a.

I checked on line and the clutch was around $100.00 and that wasn't too bad, considering it was probably only a bearing that was bad, but it had been in there a long time, so it wouldn't hurt to replace the clutch, and then if the vibration was still there, then the more expensive compressor could be replaced.

Just how much more expensive you ask. Well the imports on eBay go for $250.00 with a compressor, clutch, receiver drier, expansion valve, and some oil. The Denso OEM compressor only goes for abut twice that much, around $550-$600 and you have to add to that the clutch ($100), receiver drier ($50) expansion valve ($50) and some oil ($10) and you are looking at $300-$800 depending on whether you choose import or OEM. But wait, it gets worse. I called around and to drain and refill the system would cost $200-$250. Just in case you haven't priced R134a recently, a 12 oz can of the stuff costs $20.00 and TPTB here in California have decided that it would be a good idea to add a $10.00 core charge to the price, so two cans of R134a would cost $60.00, but you get $20.00 back if you return the cans for your core deposit within 3 months. On the bright side, homeless people could make a nice living collecting R134a cans compared to aluminum cans. So I'm looking at a grand to fix the A/C rumble, and I'm starting to grumble.

I could see right away that this would be a very expensive guessing game, so off to a local mechanic to get somebody that knew what they were doing. I figured whatever they charged to look at the problem would be well worth it. I made an appointment, and took it into the shop. After the guy looked at it, said that he didn't think anything was wrong. He checked the pressure and it was good. He checked for leaks, and said he found none. He checked the temperature in the car and it was good. He checked for oil leaks, and didn't find any. He said that the rumbling wasn't the worse he had seen, and a new one would certainly vibrate much less, but as far as he was concerned, just live with it. And then to make my day, they didn't me charge anything for checking everything.

Off I went, happy in the sense that I wouldn't have to go through the expense of replacing everything, but not so happy with the rumbly idle. I mentioned to the tech, that I was considering getting a 6" hole saw and cutting a hole in the fender well, so I could get at the compressor clutch, without having to remove the compressor, since I couldn't see any way to get the compressor out from the top. He agreed that it wouldn't come out from the top without removing the hoses. But he said that it might be possible to unbolt the A/C compressor and drop it down far enough to get a wrench on the compressor clutch. And I thought that might be worth a try.

So my question is, has anybody done this? The FSM says to remove the entire compressor to replace the clutch, and that you need a special tool to remove the clutch. Has anybody has removed one of these clutches without removing the compressor? Is the special tool needed, or can something else be used.

Appreciate any suggestions.


.

[JohnGD]

The compressor is always unbolted and swung aside for engine pulls. But I can't remember if there is enough room to work on the clutch if the engine is in place even with the fan removed.

You should be able to find the special pulley holder in parts stores. I see them ~$10 that look like:
http://www.alltradetools.com/catalog...lder-tool.html

[ajkalian]

Originally Posted by JohnGD

The compressor is always unbolted and swung aside for engine pulls. But I can't remember if there is enough room to work on the clutch if the engine is in place even with the fan removed.

You should be able to find the special pulley holder in parts stores. I see them ~$10 that look like:
http://www.alltradetools.com/catalog...lder-tool.html

Thanks very much for the info on the tool. I'll jack up the car tomorrow and remove the wheel and access cover and see how much room there is with the compressor in place. I plan on replacing the front motor mount soon so when I remove the old one I might be able to jack the entire motor around enough so I can fit the tool and a socket in there and remove the compressor pulley while it is still bolted to the engine.

I'll let you know how it goes, or doesn't go.......


.

[JohnGD]

If jacking the engine doesnt work then there are 3 long bolts that hold the compressor to the engine block. It will be easier to remove the fan and alternator first to gain access.

Once you remove the bolts you can swing the compressor a bit to get to the clutch. Maybe try removing the alternator/compressor method first and if you need more room then remove the engine mount but you shouldn't need to.

I'd be very careful with the rubber hoses. If they crack or come apart at the clamps the freon can freeze off eye balls in a second. The typical precautions are to wear splash resistant type goggle and thick long sleeves/gloves. (But be careful if you run the engine with long sleeves).

http://www.harborfreight.com/garage-...gle-97140.html

[ajkalian]

Originally Posted by JohnGD

I'd be very careful with the rubber hoses. If they crack or come apart at the clamps the freon can freeze off eye balls in a second. The typical precautions are to wear splash resistant type goggle and thick long sleeves/gloves.

I've got a full face shield mask that I use for grinding. I'll be sure to wear it. But you bring up something I've wondered about. Is the R134a under pressure, or vacuum? If it's under pressure then it will squirt out, I get that. But if it's under vacuum, it should just suck in the air, not expel the R134a.

Oddly enough I have a refrigerant vacuum pump, but I adapted it to be used in a woodworking vacuum press. After the panel is glued under vacuum, when I release the valve, there is just a small "whoosh" and the bag looses vacuum and fills with air. I wonder if that's what happens with the A/C system.

Maybe I'll go out to Pick-N-Pull and do some experimenting. That is, if they haven't already drained all of the A/C compressors.

[Stillrunning]

Originally Posted by ajkalian

Recently I've noticed that when I come to a stop and the engine idles there is a noticeable shaking coming from the engine compartment.

Have you considered that the idle-up for A/C operation may not be working? Too low an idle with the compressor working will cause the engine to shake. What's the idle when A/C on and off? The fans also put increased load on the engine. The ECU is supposed to adjust idle through the IAC valve.

Originally Posted by ajkalian

Is the R134a under pressure, or vacuum?

Always under pressure. The higher the temp the higher the pressure.

[ajkalian]

Originally Posted by Stillrunning

Have you considered that the idle-up for A/C operation may not be working? Too low an idle with the compressor working will cause the engine to shake. What's the idle when A/C on and off? The fans also put increased load on the engine. The ECU is supposed to adjust idle through the IAC valve.



Always under pressure. The higher the temp the higher the pressure.

OK, thanks. I'll be careful around the hoses. I've got some welding gloves to go with the face shield.

The idle is OK, it's around 700-800 based on the tach and does increase when the compressor kicks in. If I tap the throttle a bit and run it up to 900-1000 then the rattle settles down quite a bit. The puzzler is that if it was a faulty compressor or bearing in the clutch, you would think it would get worse as the RPM's go up. At highway speeds there is no growling, or vibrating at all.

I just wish the compressor was in an easier place to remove and inspect the clutch. What a PITA.


.

[ajkalian]

Originally Posted by JohnGD

If jacking the engine doesnt work then there are 3 long bolts that hold the compressor to the engine block. It will be easier to remove the fan and alternator first to gain access.

Once you remove the bolts you can swing the compressor a bit to get to the clutch. Maybe try removing the alternator/compressor method first and if you need more room then remove the engine mount but you shouldn't need to.

I removed the tire, and inspection cover today to get a close look at what was where. My idea of drilling a 6" hole to access the clutch is a non-starter. The placement of the clutch is right on the bend of the frame, and cutting a 6" hole in it would weaken the frame substantially.

There's not too much room under the compressor to drop it after it is unbolted. It looks like I can get to the three bolts holding the compressor from the top, and when I replace the front motor mount, and remove the oil filter, (oil change coming up anyway) would leave quite a bit of room to move the unbolted compressor side to side. With it unbolted, there might be enough room to get one of the special tools on the clutch so it can be removed without having to disconnect the R134a lines.

But then I got to thinking. Yea, I know, dangerous some times. Anyway, if the bearing on the clutch was bad it would rumble when the A/C is not engaged, which it does. But when the clutch engages, then the clutch bearing isn't spinning and is locked in place by the magnet to the compressor. But the rumbling gets worse when the clutch engages. So it stands to reason that both of them are bad.

So it would make little sense to go through all that effort and expense to change out the clutch and then have to come back and do it all over of the rumbling didn't go away with just a clutch change.

It looks like I'm going to have to bite the bullet sometime and replace both the compressor, clutch, and the receiver drier. But as long as it cools and heats, and doesn't start to squeal, I'll just live with it. FML


.

[JohnGD]

Maybe the refrigerant level is low? Do you see bubbles in the sight glass when the compressor is running? If so maybe add 1/2 can. See if the noise goes away. Yeah otherwise drive it until the compressor quits before replacing.

[fenixus]

yeah, check the refrigent level first, look at the sight glass on top of drier receiver tank. with compressor engaged (not cycled off at moment) it should be look clean and clear. immediately after compressor cycles off there should be some bubbles present for a brief moment.

if yours looks hazy all the time then it's low on R134a.

you can also check the Low side pressure easily with reusable gauge from cans like that:

Interdynamics Arctic Freeze 17oz (contains synthetic oil and additives for removing moisture and acid).

just forget about using the "reusable" dispenser (still works as a gauge) with normal size wider cans, it won't work as the long handle will lock against the wider can's body! and you will have to waste all the refrigerant to remove learned it the hard way...

here is a chart, testing scenario depends on ambient temperature and should be done at engine idling, windows rolled down (or doors opened wide) and AC set to max cold, recirc and fans at full blast:

source: http://www.idqusa.com/faqs.php?faq=9...&category_id=7

[ajkalian]

Originally Posted by JohnGD

Maybe the refrigerant level is low? Do you see bubbles in the sight glass when the compressor is running? If so maybe add 1/2 can. See if the noise goes away. Yeah otherwise drive it until the compressor quits before replacing.

I haven't checked the sight glass, but I'll do it tomorrow and report back.

[ajkalian]

Originally Posted by fenixus

just forget about using the "reusable" dispenser (still works as a gauge) with normal size wider cans, it won't work as the long handle will lock against the wider can's body! and you will have to waste all the refrigerant to remove learned it the hard way...

Thanks, good info. But I had to laugh about wasting the refrigerant. I usually keep a can around to freeze things, and it was getting low, so I figured I'd bite the bullet and get another can. BTW, if you get this stuff to freeze things, be sure to NOT get the R134a that has oil in it. It makes a real mess, let me tell you.

Anyway, when I got the new can, I noticed that there was some sort of magic blue non leak save the planet cap. So I figured I'd do my part, and get one and put it on the can that I had, so it wouldn't leak. So stupid me, I unscrewed the valve thinking that there would be some magic that would seal the prior valves puncture of the can, and well, it didn't and the shit started to come out like nobody's business. I scrambled to get the save the earth blue valve on but ended up looking like and idiot with this can shooting stuff and me trying to cap it with the save the earth blue thingie.

By the time I got it done, there was maybe a quarter of the can left. But at least I know now to put the save the earth blue thing on first, then the on/off valve. As the old saying goes, learn something new every day.


.

[fenixus]

Originally Posted by ajkalian

Thanks, good info. But I had to laugh about wasting the refrigerant. I usually keep a can around to freeze things, and it was getting low, so I figured I'd bite the bullet and get another can. BTW, if you get this stuff to freeze things, be sure to NOT get the R134a that has oil in it. It makes a real mess, let me tell you.

Anyway, when I got the new can, I noticed that there was some sort of magic blue non leak save the planet cap. So I figured I'd do my part, and get one and put it on the can that I had, so it wouldn't leak. So stupid me, I unscrewed the valve thinking that there would be some magic that would seal the prior valves puncture of the can, and well, it didn't and the shit started to come out like nobody's business. I scrambled to get the save the earth blue valve on but ended up looking like and idiot with this can shooting stuff and me trying to cap it with the save the earth blue thingie.

By the time I got it done, there was maybe a quarter of the can left. But at least I know now to put the save the earth blue thing on first, then the on/off valve. As the old saying goes, learn something new every day.


.

LMAO thanks for good laugh
yeah, I probably didn't look too smart either unscrewing the non-working dispenser from a full can of r134a

[ajkalian]

I checked the site glass and it was full of bubbles. I put a gauge on the low side and took a reading. The outside temperature was 85 degrees. Doors open, A/C on high. It was 20 psi, so I added some R134a. I checked the pressure again, and it was only 25 psi so I cracked open a new can and began to fill. I did a little at a time until the bubbles in the site glass went away, and then took another reading. It was only 35 psi which was at the bottom of the range, but I didn't want to overfill it so I stopped.

I also noticed that with the A/C on high, the gauge read 32-35psi, but when the A/C was turned off it was 45 psi. And to be honest I don't know whether you are supposed to fill it with the A/C running or not. I would think it should be when it is running full blast, but I put almost 14 oz of R134a into it, and I think the capacity was only 22 oz.

According to the chart below I passed all of the sniff tests except #6, kinda. I was by myself, so I'd shut off the A/C then run over to the front of the car to check the site glass. It was always clear. I don't know how long the refrigerant is supposed to foam, and then clear up. But after about 3 times of turning off the A/C, running to the front of the car and looking, I just gave up. Besides I felt like and idiot. Turn the key off, run, run, put your head in the engine compartment. Do that two or three times, and the neighbors will begin to wonder what you are up to.




I took some readings about the temperature differential between the high side and the low side in Item #4. I wasn't sure what the FSM meant, but I took the readings for the high side on the tubing where the site glass was, and the low side readings on the tubing where the low side port is. With the A/C running full blast the temp on the low side was 63-70 degrees, and on the high side it was 96 degrees. With the A/C off the temp on the low side was 75-82 degrees and on the high side it was 97 degrees. But I don't know what the temperature differential should be.

The FSM is really vague about it. "Temperature between compressor inlet and outlet is noticeably different"

And now that the system is all recharged did the rumbling go away? Sadly it didn't. It's still there, just as it was before, so it still looks like a new A/C compressor and clutch is going to be on my list of things to do at some point in the future.

.

[fenixus]

reading is only meaningful if compressor is running. when compressor cycles off I've seen readings as high as 150psi on the low side, it's meaningless.

35psi is still on the low side. you should pump it up until you see around 45-55psi on the low side when compressor runs at full blast.

what is your idle speed at, steady 700ish with all accessories off? wondering if the IAC valve being dirty could have anything to do with too low idle and AC compressor rumbling? but I think you've cleaned it already thoroughly?
just to make sure, you are filling it with refrigerant+oil, right? not a plain freon with no oil?

could be that your problem is in fact the AC compressor. If that's the case, it will be around $600 to get an OEM remanufactured one.

EDIT:
FSM way (at 1,500rpm) readings are NOT to be compared with aftermarket way - they are the same thing essentially, but OEM spec pressure reading numbers differ because of different conditions (engine speed) from common (generic) aftermarket readings (measured at normal idle).