AC compressor help needed (1 Viewer)

[TTCruiser]

Hi all,
My 2000 LC has 240,000 miles on it currently. The AC comes on strong and ice cold. But the clutch is sometimes very loud when it engages. Most of the time it engages just barely loud enough to hear inside with the windows up, but every once in a while it is loud and I feel a slight vibration. Also here is a rattling noise during slow easy acceleration around 15-20 mph with the AC on. Noise goes away instantly when AC is turned off. The truck is currently at the mechanic shop, but he is hesitant to replace it if those are the only symptoms and it is a pretty high cost repair. He quoted me about $900.
What would you all do? Have it replaced for peace of mind, or get some miles out of it and wait for more symptoms? I do frequently take the family (wife and two young daughters) on trips through the SoCal and Arizona desert.
Also, the repair would be a “business expense”. I think that’s making me lean a little more towards having it replaced.

 

[nissanh]

I believe my 2000 with 238K miles have the same symptoms. I replaced the clutch bearing with a NSK bearing but the sound is there. It is more of a mechanical and internal than a bearing related is what I feel. In worst case, if the AC compressor freezes, there is a sensor at the back of the compressor that sends a signal to ECU to disengage the compressor. No other toyota I own have this sensor wire on the AC compressor. That sensor monitors the rpm of the compressor and engine. When there is a mismatch, ECU turn off the power.

We have experienced mudders here and I am sure they will explain more about this sensor. I felt relieved after hearing about this sensor as it will shut off the compressor in an AC compressor failure. Otherwise this one drive belt worries me.

 

[TTCruiser]

I believe my 2000 with 238K miles have the same symptoms. I replaced the clutch bearing with a NSK bearing but the sound is there. It is more of a mechanical and internal than a bearing related is what I feel. In worst case, if the AC compressor freezes, there is a sensor at the back of the compressor that sends a signal to ECU to disengage the compressor. No other toyota I own have this sensor wire on the AC compressor. That sensor monitors the rpm of the compressor and engine. When there is a mismatch, ECU turn off the power.

We have experienced mudders here and I am sure they will explain more about this sensor. I felt relieved after hearing about this sensor as it will shut off the compressor in an AC compressor failure. Otherwise this one drive belt worries me.

That’s really good to know about the sensor. Being stranded with my kids and wife is the main thing I am trying to avoid.

 

[nissanh]

That’s really good to know about the sensor. Being stranded with my kids and wife is the main thing I am trying to avoid.

Wait for experts to comment. The forum recently had a discussion about failing compressor even after replacing a new compressor unit. Someone stated that aftermarket compressors have faulty sensors, hence ECU shut off power to the compressor clutch.

 

[TTCruiser]

Wait for experts to comment. The forum recently had a discussion about failing compressor even after replacing a new compressor unit. Someone stated that aftermarket compressors have faulty sensors, hence ECU shut off power to the compressor clutch.

Ok I’ll wait for the experts to chime in. We would be using a Denso unit if we go forward with the repair.

 

[flintknapper]

That’s really good to know about the sensor. Being stranded with my kids and wife is the main thing I am trying to avoid.

It's not fool-proof. Your compressor DOES have a 'lock out' sensor and if properly working 'should' deactivate the magnetic clutch that turns your compressor. So as long as the issue (discrepancy in speed) were due to the compressor seizing (internally) it would save your serpentine belt. BUT....IF the problem is with the bearing in the pulley (that normally free wheels) and IT seizes up, you lose your serpentine belt anyway.

It's a no-brainer, if you can claim it as a business expense, then have the compressor replaced and the system refreshed and waste no time doing it.

 

[TTCruiser]

It's not fool-proof. Your compressor DOES have a 'lock out' sensor and if properly working 'should' deactivate the magnetic clutch that turns your compressor. So as long as the issue (discrepancy in speed) were due to the compressor seizing (internally) it would save your serpentine belt. BUT....IF the problem is with the bearing in the pulley (that normally free wheels) and IT seizes up, you lose your serpentine belt anyway.

It's a no-brainer, if you can claim it as a business expense, then have the compressor replaced and the system refreshed and waste no time doing it.

Yes that makes sense. Not worth the risk and hassle to me. I’ll have it replaced. Thank you for your input.

 

[TTCruiser]

So.... I had the compressor replaced with a denso unit. The clutch is definitely quieter when it engages, but the rattling noise is still there, quieter but still there. I hear rattling only when the ac is on, getting up to speed, and cruising around 10-20 mph. Seems to go away around 20mph. I can turn the ac off when I hear the noise and it will instantly go away. Any ideas what it could be?

 

[AZSlim]

Ever figure this out?