AC Compressor problem. Clutch? Bearings?

[slvr00gt]

My AC compressor still blows nice cold air, but every time I drive for an hour or so, it starts to drag and bog down the engine. When I slow down, revs jump up and down.
Is the AC clutch going bad? Compressor bearings?

Thanks!

 

[BobHyatt]

My AC compressor still blows nice cold air, but every time I drive for an hour or so, it starts to drag and bog down the engine. When I slow down, revs jump up and down.
Is the AC clutch going bad? Compressor bearings?

Thanks!

There are several possibilities.

1. If you over-charge, the compressor can become very difficult to rotate, and it will definitely be a load on the motor, although this will also destroy the compressor if it continues for any length of time.

2. rapid cycling could be a cycling switch problem, it is a cheap repair and requires no special A/C handling experience...

3. It is doubtful the clutch is a problem, although if you listen carefully you could potentially have a bearing issue on the bearing that supports the pully when the clutch is not engaged. If this bearing starts to go out, it can become very difficult to turn, but usually it is just a matter of minutes or hours before it seizes and throws the belt off...

 

[COramprat]

I've found that when the clutch bearings go you have a rattling from the pulley cover as it begins to fall apart. You should be OK if you don't have the metal rattling as far as clutch and bearings go.

My car was doing the same thing yesterday. Since my clutch is relatively new I'd look at the other two options Bill threw out there. If you haven't charged it recently then you might look at the cycling switch.

 

[slvr00gt]

Thanks,
I checked the refrigerant pressure, it is in the "low" normal range.
Is there way to check cycling switch? Or just change it and see what happens?

 

[BobHyatt]

Thanks,
I checked the refrigerant pressure, it is in the "low" normal range.
Is there way to check cycling switch? Or just change it and see what happens?

Disconnect the switch (it is on the receiver/dryer/accumulator bottle by the passenger-side firewall.) Jumper the two pins in the connector and see if the compressor runs continually. Note that you can freeze up the evaporator core since the compressor will not cycle if you do this, so I would not run like that for hours or days... If things sound more normal like this, replace the switch. Under 20 bucks at most auto parts stores. There's a valve under the thing so you can remove it without losing freon...

 

[slvr00gt]

There are several possibilities.

1. If you over-charge, the compressor can become very difficult to rotate, and it will definitely be a load on the motor, although this will also destroy the compressor if it continues for any length of time.

2. rapid cycling could be a cycling switch problem, it is a cheap repair and requires no special A/C handling experience...

3. It is doubtful the clutch is a problem, although if you listen carefully you could potentially have a bearing issue on the bearing that supports the pully when the clutch is not engaged. If this bearing starts to go out, it can become very difficult to turn, but usually it is just a matter of minutes or hours before it seizes and throws the belt off...

Yep! cycling switch it was! 3 minute repairs and no more problems..... Unfortunately, prior to posting question I convinced myself that compressor clutch went bad and got a new compressor off ebay. It is lying pretty in my garage ... unused. Good thing it was relatively cheap.