Discovery 2 Chirping Pulley

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
Truck has a chirping sound getting progressively louder. Did the screwdriver trick, sounded like the tensioner pulley, but no dice when I replaced it, luckily that's a cheap one. Could be one of the idlers but it really sounds like the AC compressor. The only thing is that the AC works and the noise doesn't change whether the clutch is engaged or not. I'm hoping that's a good sign the AC is actually ok. No abnormal noise that I could hear with the screwdriver either. I think my real question is what can I do to eliminate the compressor as the issue?
 

jprover2

Well-known member
Apr 8, 2017
146
10
Birmingham,Al
If it has not already been done, remove the serpentine belt and turn each pulley by hand. You will be checking for anything other than smooth when you turn them. Inspect the belt also.
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
I'm trying to verify which idler pulley is which. I believe the one just below the tensioner is PQR500060 and the one between the AC and PS pump on driver side is PQR101150K
 

jymmiejamz

Well-known member
Dec 5, 2004
6,008
361
35
Los Angeles, Ca
Make sure that the power steering pump isn't coming apart. I've seen where the shaft comes partially out of the steering pump which causes belt noise.
 

JohnB

Well-known member
Oct 18, 2007
2,292
12
Oregon
My ac bearing was so tight it made the belt drag and caused an over heat. The tell tell sign is if the its harder than usual to turn your steering wheel.

I'd replace the other 2 idler pulleys anyway as they all wear at some point.
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
My AC compressor pulley moved pretty freely. I need to check the ps pump and the water pump, but I will probably replace the two idlers, cheap and easy to do.
 

coop74

Well-known member
Dec 10, 2015
287
7
Alcoa TN
A quick diagnostic tip... get a spray bottle and put some tap water in it. Squirt the belt while it is running and see if you chirp goes away. If it does what you actually might need is just a new belt. Since it is a low dollar diagnostic i would recommend you try it first. It has saved more than a few the cost of some expensive parts they did not actually need.
 

jymmiejamz

Well-known member
Dec 5, 2004
6,008
361
35
Los Angeles, Ca
A quick diagnostic tip... get a spray bottle and put some tap water in it. Squirt the belt while it is running and see if you chirp goes away. If it does what you actually might need is just a new belt. Since it is a low dollar diagnostic i would recommend you try it first. It has saved more than a few the cost of some expensive parts they did not actually need.

In most cases, spraying anything on the belt will make the noise go away, even if something other than the belt itself is causing it.
 

coop74

Well-known member
Dec 10, 2015
287
7
Alcoa TN
straight up plain water will only silence the belt for a few seconds. If it is a bearing in the pulley it will not silence a bearing.
 

coop74

Well-known member
Dec 10, 2015
287
7
Alcoa TN
Worth a try, but the belt is new, maybe a thousand miles on it. Waiting for a little warmth then I'll dig into again

I have found certain belts just chirp. The water test will tell you quickly however. Again it is free and takes as long at it takes to fill the squirt bottle and open the hood. For those that seem to normally are very sensitive to pulley alignment.
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
I'll get a pic of it later, but it's routed right.

PS pulley turns smooth but not easy. Should it turn freely like the AC compressor or water pump? Water pump pulley has about 1/8" of play up and down but turns smooth and quiet. I might have found a water pump ready to fail, but I don't think it's the source of the noise.
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
I've got a water pump and viscous fan clutch on the way. The sound has gotten progressively worse over the past few months and I know that pulley wasn't like that when I did the belt, so maybe under tension the pump bearing is the source of the noise.
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
New water pump fixed the noise but now the truck wants to overheat. Never done that before. Also, tried turning heat on, but no hot air. Must be related, could it be air in the system? System is pressurizing, hoses are hot so coolant is flowing. I'm at a loss On this one
 

jsonova99

Well-known member
Apr 14, 2005
1,683
0
47
Snow Hill, MD
Didn't check lower hose, did some reading, hoping this is air in the system, was fine before the pump replacement. Temp got up to 210 when I shut it off. I knew something was wrong once it got into the 190s never gets that's hot unless sitting. Going to let it cool and try bleeding the system again.