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Explorer serpentine squeaking. How to locate it?

casadejohnson

Bronco Alchemist
Joined
Jan 21, 2005
Messages
3,587
I have had my Explorer serpentine on for a while and everything works great except I have a squeak that I can't locate. I replaced all of the pulley bearings and the squeak did not go away. I thought it was coming from the lower idler pulley and replaced that bearing a second time. I used some WD40 on the pulleys and the sound goes away for a short time. The problem is that it does not matter which pulley I spray. The lube is being carried by the belt to all of the pulleys. If I spray the belt itself, it gets very quiet. It sounds like the fan slows down. So I'm wondering if the noise could be from the fan clutch? Maybe from the water pump?
 
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casadejohnson

casadejohnson

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Jan 21, 2005
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3,587
No, I'm not sure its not the belt. I guess I could get another one but the belt is pretty much new. It does not have more than a few hundred miles on it. That said, It has always made the noise since the install so a belt squeak is not out of the question. I can only describe the noise as a chirping sound. Is a squeaking belt a common thing? what would cause a squeaking belt?
 

EricLar80

Bronco Guru
Joined
Jun 14, 2001
Messages
2,170
To find a bad pulley, use a long screwdriver. You can put it on metal near the suspected bad part, put your ear up to the other end, and listen. It will be loud when you get near whatever is failing. Just be careful of moving parts while the engine is running...

If a belt is squeaking, it could also be due to a bad bearing or component causing extra force to turn.

Eric
 

73stallion

Bronco Guru
Joined
Mar 5, 2004
Messages
16,786
Loc.
Eugene, OR
You can also listen thru like a piece of fuel line or vacuum tube. But yes it is possible for a belt to make a chirping sound. There's several cars here in my neighborhood that sound like they have birds under their hoods.


Sent from my iPod touch using Tapatalk
 

Ratch

Sr. Member
Joined
Nov 1, 2007
Messages
694
Sounds to me like you have a belt squeak. The fan sounds like it is slowing down because it is. The wd40 is causing the belt to slip on the pulleys.

First of all wd40 is not what you want to use to try to quiet a belt noise, probably the worst, and the so called "belt dressing" is not much better. The best would be a good dielectric grease . I always used the ford high temp caliper slide lube/ dielectric. Just a little pinch on your finger tip and rub it in a couple spots on both sides of the belt.

Like you will find with other parts, all belts are NOT created equal. I have seen the cheap belts start squeaking/ squalling as soon as they are put on. You want to use a Gates or NAPA brand which is made by Gates. The extra money spent will be made up by increased belt life.

p.s. Clean the wd40 off the pulleys with brake cleaner when you change the belt, it will soak into the belt and cause it to slip.
 

chadomatic

Jr. Member
Joined
Jun 25, 2010
Messages
145
Loc.
St Paul
I agree on the dielectric. And he is right the ford stuff works awesome. It will get you buy untill you get a good belt.
 

RRRAAAYYY2

Bronco Guru
Joined
Nov 10, 2004
Messages
1,684
Loc.
Brantford, Ontario
To find a bad pulley, use a long screwdriver. You can put it on metal near the suspected bad part, put your ear up to the other end, and listen. It will be loud when you get near whatever is failing. Just be careful of moving parts while the engine is running...

If a belt is squeaking, it could also be due to a bad bearing or component causing extra force to turn.

Eric

A noise in the front end accessories will travel through the belt. So a bad water pump bearing could mistakenly be heard in the alternator, very easily. We had stephascopes(sp) just for locating noises (Like a screwdriver on steriods), havent been able to use them in 15 years.
 
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casadejohnson

casadejohnson

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Jan 21, 2005
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3,587
I know the WD40 is bad, I was just attempting to locate the noise with it. I'm going to try a new belt. I'll can't remember the length so I'll pull it off and stop at NAPA on the way to work. got my fingers crossed that the belt is the problem and this will take care of it.
 

RRRAAAYYY2

Bronco Guru
Joined
Nov 10, 2004
Messages
1,684
Loc.
Brantford, Ontario
A couple of things to check for on a serpentine system:

1.) Bad tensioners. Approxiamately 40% of all vehicles on the road right now, have a bad belt tensioner on them. They were only designed to last about 50K miles, and some are prone to failure at like 30K miles.
The expensive test tools for these are not very accurate. The best way to check them is visually. Most have a hash mark on them, if not, you can just draw a line across the arm/base with black marker. Start the vehicle up. The tension arm should be moving slightly back and forth all the time when the engine is at idle. If it is not, it is not doing what it is designed for.
Not replacing it will cause premature bearing failure in the next device on the belt, which is typically the alternator. It will also cause pulley wear throughout the system.

2.) Pulley wear: Another very, common over looked issue in serpentine systems. If you look at a new pulley, the peaks on the grooves in the pulley are very sharp. Over time they round off, sometimes becomeing like flat spots on the top of the grooves.
Most of the power transfer happens on the top of the grooves, the peaks. If they are rounded off or worse, become flatten, the pulley cannot transfer the power properly. It then squeaks, or more like a sliding noise.

So I would check both of those items. Putting any petroleum based product on rubber is not recommended.
 
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casadejohnson

casadejohnson

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Jan 21, 2005
Messages
3,587
I read about the belt tensioners going bad and watched for movement as suggested. I believe it's functioning properly. I'll check on the pulley wear after work. Thanks for the help. I'll let you know what I find later this evening.
 

kurtbrazee

New Member
Joined
Apr 11, 2010
Messages
38
Loc.
Lansford, pa.
It's not often that a serp. belt itself will squeek, but it is not out of the question. The adjustment on a serp is dependent on the tensioner. so i would start there. Assuming that there is not excess drag being caused by one of the accessories. Just a tip, I have fairly extensive experience in the auto industry and have never had a problem with Gates belts. Dayco belts however were problematic at times.... good luck. also check that pulleys are on a parallel plane....... you can use a straight edge for that.......good luck..
 

needabronco

Bronco Guru
Joined
Jul 2, 2004
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6,411
Loc.
Prescott/Farmington
BTW you can replace just the bearings on those pully's, the part number is XX-203, the XX changes with the brand. A machine supply shop will have cheap bearings from $2 each to the best at $10 each. I try to keep a couple of spares to swap out. My idler bearing seemed to go through 3 in a short succession right after I installed my efi...
 

RRRAAAYYY2

Bronco Guru
Joined
Nov 10, 2004
Messages
1,684
Loc.
Brantford, Ontario
BTW you can replace just the bearings on those pully's, the part number is XX-203, the XX changes with the brand. A machine supply shop will have cheap bearings from $2 each to the best at $10 each. I try to keep a couple of spares to swap out. My idler bearing seemed to go through 3 in a short succession right after I installed my efi...

I would take them to an alternator rebuilding shop, as they often sell them to bearing suppliers at a hefty market up. :) Something to do with my supplier buys a truck load of 6303 or 62o3 a week, my local bearing house goes through a case in a month or two, and we are a city of 100,000.
 

Amac70

ME
Joined
Mar 27, 2002
Messages
3,269
I would check for alignment issues. My serp squeaks like hell. i change a belt every 400 miles or so. they ususally go about 200 before i get a slight squeek then chirp. You will see fraying a bit on the outside edge of belt. i have one thing that is just a little off. since it takes me all year anymore to drive 400 miles i don't fix it (i will soon).
 

Ratch

Sr. Member
Joined
Nov 1, 2007
Messages
694
It's not often that a serp. belt itself will squeek, but it is not out of the question. The adjustment on a serp is dependent on the tensioner. so i would start there. Assuming that there is not excess drag being caused by one of the accessories. Just a tip, I have fairly extensive experience in the auto industry and have never had a problem with Gates belts. Dayco belts however were problematic at times.... good luck. also check that pulleys are on a parallel plane....... you can use a straight edge for that.......good luck..

This man is correct. If the tensioner pivot is loose or looses tension then it will cause all kinds of issues with the belt. Dayco belts suck bawls.
 
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casadejohnson

casadejohnson

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Jan 21, 2005
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Long day at work and I just got home. I did get to NAPA and picked up a good belt from them. It better be good because it was $44 with tax. If it helps me get rid of the chirp it will be worth it. I'm going to toss back a quick Burger King gut bomb and get to work on it. I need this baby fixed tonight if I'm going to make it to the Mountains for a snow run with the rest of my compadres from Colorado Classic Bronco's. I'll report back in a while.
 
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casadejohnson

casadejohnson

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Jan 21, 2005
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Well, good news first. So far at idle and in my trip around the block the noise is gone! I took off all the idler pulleys and cleaned them up. I also had one bearing that looked like it might not be in perfectly straight so I pressed it out and then reinstalled it. It looks straight now. I also took the tensioner apart and cleaned it out. It had a bunch of dirt packed in it so I cleaned it out and lubed it up inside. The bad news is , I think the pulley on the tensioner is slightly bent. With no belt on, it looks like it wobbles a little when you spin it. After I put the new belt on, I started it and watched the pulley and it does not appear to wobble at all. Maybe the belt tension is enough to keep it straight? Either way, I'll replace it sometime this weekend but I think it will get me through the wheeling trip tomorrow. We will see if it stays quiet and go from there.
 
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casadejohnson

casadejohnson

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Jan 21, 2005
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Its been over 2 years since I started this thread and my belt tensioner needs to be replaced again. To be fair, I used a junkyard replacement last time. So, long story short the squeak is back and this time I'm replacing the pulley and tensioner with a new one. I can buy an aftermarket replacement for about $45 or I can order the Motorcraft replacement for about $80. I was going to go the aftermarket route but I have been disappointed with Autozone (Duralast) replacement parts in the past so I thought I would see if anyone had run the Autozone version and if so, is it decent or just another Chinese made POS.
 

DirtDonk

Contributor
Bronco Guru
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Nov 3, 2003
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47,275
Be interested to hear what others have to say.
I'm working on a 4.6 right now where literally every component on the accessory drive that spins needs replacing. First time I've ever seen this on a vehicle, but with 120k on the clock, if it's all original that might be what's going on.
However, the fact that I'm having to replace the A/C compressor for the second time in the car's life, leads me to think that the tensioner is not helping.
It "feels" good and smooth (which is a feat in itself after this many miles), but the original factory spring is so much stiffer than the aftermarket replacement piece, I'm wondering if the tensioner is not the reason for the trouble?

Good luck with yours. At least you've had a decent run of quiet functioning. Hopefully the next one will be even longer.

Paul
 
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