[tired96]

On the '96, I have a noise on the belt side of the engine. It's loudest when the car is cold and goes away after running a while. The noise will come back after a hard stop or hard cornering. It has a metallic sort of grinding noise to it.

I have pulled the belt off. There is no noise with the belt off and the engine running. The spring loaded idler is 15K miles new. The stationary idler is brand new. The water pump, ps pump and alternator turn smoothly by hand with the belt off.

I searched with a stethoscope. The noise seems loudest when touching the air conditioner compressor case. It's loud all the way to the block. The thing is the noise sounds exactly the same weather the compressor is engaged or off. Does this make sense? I thought there were different bearings active depending if the clutch is on or off.

 

[jw89sho]

Sounds like you need new bearings in the compressor. Best to service it now, before it seizes and snaps your belt.

 

[tired96]

That's what I was thinking.... The sound is similar to a brake lathe.. Where is metal touching metal? Is the clutch assembly grinding against the coil? Why both when the air is on and when it's off.

How big a job is it to reach the a/c compressor? Can I swap this from above without having a lift? I've got the tools and gauges to recover and recharge the system.

 

[jw89sho]

year? engine?

The noise is coming from the bearings that support the pulley, on the periphery of the clutch and pull-in coil. Once the compressor is out, you may be able to get the bearings and replace just that part, or get a rebuilt/new compressor at the parts house. May consider a low mileage unit from a junkyard.

As I understand, most G3/4 cars are serviced from the bottom, may have to lower subframe partially.

 

[tired96]

Thanks everyone for the help. I took the car to K & K Automotive in Frederick to have a new Ford compressor, new o-tube, new accumulator and evacu/recharge. We picked the car up tonight. A mile down the road, the car overheated with the temperature gauge had reached 90% of range. I got all the way home, twenty miles, to get a call from my wife, "car is overheating, come get me". She knows the drill on temperature warnings so she stopped the car right away. By the time I get to the car, the gauge is on the cold mark.

I drive back towards the shop. Within half a mile, the gauge is climbing fast. The heater is still blowing cold air! We stopped and waited at the side of the road several times with the engine switched off to cool down. Once at K & K Automotive, they add some coolant, saying it was air locked.

I confront them about testing the car. I don't see how they could test drive the car or even charge the A/C without noting the overheating issue. I don't understand that a mechanic wouldn't verify the heater blows warm before releasing the car when the coolant system has been drained as part of the service.

On a hunch, I popped the hood and checked the A/C to see if it was turning with the A/C turned on. The clutch would not engage, not even to cycle. I don't see how they could draw a vacuum on this system, charge 3/4 pounds of refrigerant in it, never see an overheat condition and then have the refrigerant so low the compressor won't engage.

How great is my risk of head gasket failure from this overheating episode?

The old compressor hub bearing was bad. The rattle noise on hard turns or hard stops was the loose ball bearings rising to the top of the race and spilling down the other side. The pulley had 1/8" of wobble in one direction and was better in another.