Pulley Chirp

[NurseGuy]

So, i just picked up a 1997 4.6 GT from the 2nd owner. It has been babied and very well taken care of. Guy said that AC blew cold. When I went to pick it up, he said that in the last 5 days it developed an intermittent chirp from what sounds like the tensioner pulley. The AC compressor is also not working properly as evidenced by it not getting cold. The fans blow, then freon is full (according to the gauge on the artic ice ac recharge bottle). Is it possible that the chirp I am hearing from time to time is the ac compressor, or would it more likely be from the tension pulley? Like I said, it has only recently started, is not constant, and all other belt driven accessories are working as they should. The fella was very adamant that the AC has been blowing cold as he was using the car as a daily driver up until about a month ago when he bought a small truck. Aside from this, the car is in AMAZING shape. I'm not running the AC in fear that I will mess it up or cause extra load on the belt and tensioner. I don't want to screw up this engine as it is currently running like a sewing machine. It is hot as hell here in South Georgia (110* today) and I NEED AC! Help......

 

[wmburns]

then freon is full (according to the gauge on the artic ice ac recharge bottle).

FWIIW, it's not possible to tell if an AC system is correctly charged by looking at a simple pressure gauge on the low pressure side. The Freon pressure will be affected by things such as (but not limited to):

• outside air temperature
• inside air temperature
• Air flow over the radiator
• Air flow inside the cabin
• The expansion valve.

IMO based upon your post and the information given you can't say with certainty that the AC system is fully charged.

What I frequently do when working with noises is to use a mechanic's stethoscope. Touch the probe to the part in question. It's amazing how it isolates the noise from a specific part.

I have also worked with several of my Fords that made noises from the AC Clutch. The bearings that support the mid section wear out and allow the hub to "run out" and rub the pressure plate. The trick for a DIY job is to replace the outer section with a name brand Ford unit. Do not use an aftermarket replacement. Why? Because the aftermarket units have a different magnet unit. The biggest PIA part of the job is pressing on and off the magnet. So if the magnet is still good and can be re-used it will save a TON of effort. Then the AC hub bearings and friction plate are an easy fix.

 

[NurseGuy]

So, putting the AC compressor to the side, could the "chirp" I'm hearing be coming from the tensioner or idle pulley? Also, if it is a pulley chirping, or ac compressor, is it okay to drive??

 

[wmburns]

So, putting the AC compressor to the side, could the "chirp" I'm hearing be coming from the tensioner or idle pulley? Also, if it is a pulley chirping, or ac compressor, is it okay to drive??

Can you say mechanic's stethoscope? The tool is not expensive and will last a life time. Once you own one it's surprising what other noises it can help locate.

Lisle 52500 Mechanic's Stethoscope
Amazon product ASIN B0002SQYSMView: https://www.amazon.com/Lisle-52500-Mechanics-Stethoscope/dp/B0002SQYSM/ref=sr_1_4?crid=2KFW3C7HELG59&keywords=mechanic%27s+stethoscope&qid=1559034977&s=gateway&sprefix=mechanic%27s+stethoscope%2Caps%2C202&sr=8-4


I don't know how you can expect anyone out in Internet land to be able to answer a question like that without ever looking at it. If you are concerned about safety then the services of a professional mechanic should be considered.

 

[NurseGuy]

I understand the concept of the stethoscope, but, I do not feel competent enough in my mechanical knowledge to diagnose it myself. Now, a human body....sure. I just want to know that my driving it to and from work isn't going to f*ck it up.

 

[NurseGuy]

it was the tensioner. Went ahead and replaced idle pulley as well and a new belt. Also new AC compressor, orifice tube, and dryer. She is now running like a champ and freezing my nads off! This South Georgia heat don't play! It was 110* today and is supposed to be hotter than that tomorrow!