My car has been making a high pitch squeal sound for a while at least 6 months, maybe longer. It is not very noticeable when the vent is running, but when it is off you can hear it. It is not a grinning/moaning sound as I have heard in numerous K based steering systems, it sounds kind of fabric/nylonish sound like someone someone trying to rub out a stain on an pair of pants. Any ideas?

I thought it might be that the power steering fluid was getting bad so (in probably a moment of stupidity on my part in retrospect), I sucked out the old fluid in the reservoir then after reading my manual and did a Google search and replaced it with ATF+4 finding a reference to a TSB stating that ATF+4 could be used as a replacement for the MS9933. I'm not sure if this is a placebo effect, but it might be slightly quieter. Should I just have the system properly flushed with ATF+4?

 

How's the belt?

 

The belt is fine, it turns out it is the clock (spelling?) spring. No big deal.

 

Periodically when I turn on my AC (Air Conditioner) the car will vibrate significantly and it makes a sound similar to what a tractor trailer truck makes when it is engine braking. Even if I turn the AC off it will continue to do this until I shut the engine off. If I restart it (with the AC off), it will run fine. It doesn't do it everytime I use the AC, but I want to get this fixed naturally because it is becoming more frequent. Any ideas?

 

When it does it next time, open the hood and have a look at the compressor and accessory drive belts. Possible have a pulley bad.

 

Okay, what are the signs of a bad pulley? How can you tell if it is the pulley?

 

It turns out the sound was the plastic fan blades from the radiator fan so I replaced that whole unit. While it was being repaired, I also replaced the serpentine belt and A/C belt along with the pulley just to be safe. Thanks for the help.