Is AC Compressor seized OR low on refrigerant? (3 Viewers)

[leej]

I have a 2004 LX470 with about 200K miles. I was driving on the interstate (it was cold outside and I don't think AC was running, unless defrost kicked on) and heard a loud clunking noise for a few seconds (sounded like tire noise on the bumps on the side of the highway). Then I got a check AC message and AC light blinking.

I tried to turn the AC compressor by hand with the car off, and it won't turn. I'm wondering if my compressor has seized and needs to be replaced, or is it possible I'm low on refrigerant and it is in safe mode (or is this wishful thinking)???

I didn't see anything in Tech Stream that would help. I will take it to a shop next week to see what they say on refrigerant or compressor replacement...

Anyone have an ideas?

Thanks

Leej

 

[medtro]

I tried to turn the AC compressor by hand with the car off, and it won't turn.

Did you remove the belt?

I didn't see anything in Tech Stream that would help.

You can try to activate the compressor using TechStream.

 

[leej]

@medtro No, I didn't remove the belt. The pulley is spinning with the belt when the engine is running. But the BELL on the end (which spins the compressor) is not spinning (I assume this is because the AC is off and the clutch is not engaging the bell). When the engine is off, I assume the bell should spin (and spin the compressor) by hand. Let me know if I wrong on this.

When I press the AC button to engage the compressor, the engine RMPs flutter and I assume the clutch is trying to spin the bell/compressor, but it can't, and after a second or two it quits trying and the AC light blinks. I could use TechStream to try and activate the compressor, but I think I would get the same effect (the button seems to try to activate the AC clutch and spin the bell/compressor, but the compressor won't spin).

It was a fairly cold day when this occurred (50F), and the AC temp was at 70F, so I wouldn't have thought that the compressor was on/spinning, unless the defrost had switched on (I don't think it would have). Seems odd that it would seize up if it wasn't spinning (maybe it was on and I didn't know it)...

I am assuming that either my compressor is seized up, or there is some other reason the compressor won't spin. I had read somewhere that there was a safe mode when the AC was low on refrigerant that would prevent the compressor from spinning (or prevent the clutch from spinning the compressor). I'm hoping this is what is going on in my situation, but doesn't seem likely since I can't spin the bell by hand.

I'll take it to my local indy and let them put gauges on the AC and check the compressor.

If anyone else has any thoughts, or if I am wrong on my thoughts above, let me know.

Thanks

Lee

 

[flintknapper]

@medtro No, I didn't remove the belt. The pulley is spinning with the belt when the engine is running. But the BELL on the end (which spins the compressor) is not spinning (I assume this is because the AC is off and the clutch is not engaging the bell). When the engine is off, I assume the bell should spin (and spin the compressor) by hand. Let me know if I wrong on this.

Yes, you are wrong about that. First, the pulley does not spin the belt, the belt spins the pulley. IF your compressor pulley were seized it would quickly burn/shred your serpentine belt. You can't spin your compressor pulley by hand without first removing the tension from your serpentine belt. Normally, with the A/C off....the pulley on the compressor is free wheeling. When AC is called for....the magnetic clutch engages (mates the compressor clutch to the pulley) and the compressor is driven thus.

When I press the AC button to engage the compressor, the engine RMPs flutter and I assume the clutch is trying to spin the bell/compressor, but it can't, and after a second or two it quits trying and the AC light blinks. I could use TechStream to try and activate the compressor, but I think I would get the same effect (the button seems to try to activate the AC clutch and spin the bell/compressor, but the compressor won't spin).

You need to check and see if you have any AC codes. IF the compressor is trying to seize then the 'lock out' function will disable the compressor clutch. There is a speed sensor on the back of your compressor. IF engine speed and compressor speed do not closely match, it assumes the compressor is trying to seize. So in order to save your serpentine belt (which drives everything else) it disables your compressor (clutch). There is a code that relates to this.

I am assuming that either my compressor is seized up, or there is some other reason the compressor won't spin. I had read somewhere that there was a safe mode when the AC was low on refrigerant that would prevent the compressor from spinning (or prevent the clutch from spinning the compressor). I'm hoping this is what is going on in my situation, but doesn't seem likely since I can't spin the bell by hand.

There is a binary switch in the circuit (pressure switch) that will not allow the clutch to engage if the system pressure is too low or too high. So IF you were low on refrigerant the unit would not even try to engage the clutch, but this would have nothing to do with the compressor seizing (or not).

I'll take it to my local indy and let them put gauges on the AC and check the compressor.

Lee, I think that will be your best bet. Let them put a set of gauges on the system and also remove your serpentine belt to assess the compressor and pulley. Hope you get it sorted out.

 

[leej]

@flintknapper I realize the belt spins the pulley, and my pulley is spinning freely as it should since the AC clutch is not engaged? Sorry if I said something that implied otherwise.

Also, I wasn't implying that I could spin the PULLEY by hand with the belt on, but I do believe the BELL on the end will spin by hand with some effort even with the belt on (with the engine off) since it is not engaged with the pully/belt. At least it will on my LandCruiser.

I checked for codes first thing, and no codes. Again, I think my compressor is probably toast. I was just hoping for some other less expensive possibilities.

Thanks

Lee
'04 LX470
'00 LC

 

[flintknapper]

@flintknapper I realize the belt spins the pulley, and my pulley is spinning freely as it should since the AC clutch is not engaged? Sorry if I said something that implied otherwise.

Just trying to be sure we are on the same page. Serpentine belt turns the AC pulley all the time (AC clutch engaged or not). Its basically free-wheeling until the clutch engages with it.

Also, I wasn't implying that I could spin the PULLEY by hand with the belt on, but I do believe the BELL on the end will spin by hand with some effort even with the belt on (with the engine off) since it is not engaged with the pully/belt. At least it will on my LandCruiser.

Yes, sometimes you can turn the clutch (outer most portion of the compressor) by hand (with the belt on...belt does not affect the clutch but DOES prevent you from turning the pulley) if I wasn't clear about that earlier. So IF you can turn your clutch by hand then your compressor is not seized.

I checked for codes first thing, and no codes. Again, I think my compressor is probably toast. I was just hoping for some other less expensive possibilities.

Don't despair just yet. See what the shop has to say about it. But if they come back with the clutch being shot....just replace the entire compressor and not the clutch/coil assembly. Pulley bearing is another matter can be replaced by itself if everything else is OK.

Thanks

Lee
'04 LX470
'00 LC

Good luck with it, let us know what they find.

 

[medtro]

The pulley is spinning with the belt when the engine is running. But the BELL on the end (which spins the compressor) is not spinning (I assume this is because the AC is off and the clutch is not engaging the bell).

Magnetic clutch does not engage when the compressor is seized, or the system run into other issues.

 

[flintknapper]

Magnetic clutch does not engage when the compressor is seized, or the system run into other issues.

Correct. Also if the air gap is incorrect or the coil is weak.

 

[leej]

Local indy shop is telling me what I feared, compressor has seized up. $$$$.... Trying to decide if I replace compressor AND condenser/dryer and valve blocks, or just compressor with a flush, and cross my fingers...

Any thoughts or experience?

Also, any good sources for compressor (brand?), or a full AC kit????

Thanks

Lee

 

[leej]

Local shop said compressor was seized. I gambled and had them replace the compressor only ($1,000 parts labor, etc.). Everything is working great now, but I do have concerns that there could be metal or other in the condenser/dryer, etc. that may cause problems later. Hopefully all is good.

Thanks for the suggestions.

Lee

 

[flintknapper]

Local shop said compressor was seized. I gambled and had them replace the compressor only ($1,000 parts labor, etc.). Everything is working great now, but I do have concerns that there could be metal or other in the condenser/dryer, etc. that may cause problems later. Hopefully all is good.

Thanks for the suggestions.

Lee

Your compressor was NOT seized if you could turn it by hand as you indicated you might have done in earlier posts.

That doesn't mean that your old compressor wasn't worn out though. Glad you got it going.

 

[leej]

@flintknapper Sorry if I wasn't clear, I could NOT spin the compressor by hand (I did say that I believed you should be able to spin it by hand, but mine definitely would NOT). The bell/clutch would NOT spin.

Moreover, when I pressed the AC button and the clutch engaged, the engine RPMs went up and down for a second or two (I assume due to stress on the belt trying to spin the seized compressor), and then the AC light would blink and I assume the clutch stopped trying to engage. I'm pretty sure the compressor was seized. Thanks.

 

[flintknapper]

@flintknapper Sorry if I wasn't clear, I could NOT spin the compressor by hand (I did say that I believed you should be able to spin it by hand, but mine definitely would NOT). The bell/clutch would NOT spin.

Moreover, when I pressed the AC button and the clutch engaged, the engine RPMs went up and down for a second or two (I assume due to stress on the belt trying to spin the seized compressor), and then the AC light would blink and I assume the clutch stopped trying to engage. I'm pretty sure the compressor was seized. Thanks.

Yes, IF you couldn't turn it...then it was seized. What happened was the compressor 'lock out' sensor on the back of the compressor detected the difference in engine speed to compressor speed (none) and shut it down.

It's a safety feature designed to 'save' your serpentine belt. You can still lose your serpentine belt if the 'pulley' bearing seizes, but generally they make so much noise that you have 'fair warning' and can address that issue before you are left stranded with a shredded belt.

Glad you got it fixed and hope the repair holds up for you.

Thanks for the follow up.

 

[awesomeissquid]

@flintknapper, wanted to confirm the pulley (clutch assembly?) of the compressor should spin freely with the serp belt off right? I had my belt off last week and was spinning things by hand to get a feel for them and the pulley spun freely, but I feel like it was making a slight noise. Just want to make sure I get ahead of any issues.

 

[flintknapper]

@flintknapper, wanted to confirm the pulley (clutch assembly?) of the compressor should spin freely with the serp belt off right? I had my belt off last week and was spinning things by hand to get a feel for them and the pulley spun freely, but I feel like it was making a slight noise. Just want to make sure I get ahead of any issues.

Yes Sir...the 'Pulley' itself (the ribbed serp belt rides on) should turn/spin freely. It is always 'free wheeling' until the clutch is engaged which couples the pulley to the drive plate (clutch) and then turns the compressor. Even the compressor should be able to be turned by hand with the belt off (with some effort), but your question is regarding the pulley only...and the answer is yes, it should easily turn and not be rough feeling.

 

[awesomeissquid]

Yes Sir...the 'Pulley' itself (the ribbed serp belt rides on) should turn/spin freely. It is always 'free wheeling' until the clutch is engaged which couples the pulley to the drive plate (clutch) and then turns the compressor. Even the compressor should be able to be turned by hand with the belt off (with some effort), but your question is regarding the pulley only...and the answer is yes, it should easily turn and not be rough feeling.

Awesome. Guess that's another thing to add to the list.

 

[flintknapper]

Awesome. Guess that's another thing to add to the list.

Sounds like you are on top of it. Always good to check things.

 

[ls6]

Yes Sir...the 'Pulley' itself (the ribbed serp belt rides on) should turn/spin freely. It is always 'free wheeling' until the clutch is engaged which couples the pulley to the drive plate (clutch) and then turns the compressor. Even the compressor should be able to be turned by hand with the belt off (with some effort), but your question is regarding the pulley only...and the answer is yes, it should easily turn and not be rough feeling.

So if the magnetic clutch is sparking when it tries to engage, engine rpms goes up and down with every clutch lock out, and then the 'lock out' sensor steps in and stops the ac signal, safe to say the compressor has failed?

 

[flintknapper]

So if the magnetic clutch is sparking when it tries to engage, engine rpms goes up and down with every clutch lock out, and then the 'lock out' sensor steps in and stops the ac signal, safe to say the compressor has failed?

Or the Air Gap is incorrect (should be about .020").

If the air gap is correct and you are seeing the clutch try to engage, sparking of the clutch surfaces and the A/C unit kicks out (lock out sensor has activated) then yes, I'd say the compressor has seized. You can attempt to rotate it by hand also...to confirm.

 

[Yeah]

I have similar situation right now. I can turn pulley freely but when I'm pressing AC button, nothing is happening. No error codes. Can in be caused by low conditioner fluid level?
Is the armrest fridge supplied by AC compressor? because actually is heating instead of cooling.