Dodge 318 belt squeal

[Tinman74]

Have had an on going serpentine belt chirp/squeal on my 98 Dodge 318 engine for a number of years .It calls for a 100" or a 100.5" belt. It originally had a 100" and I installed a brand name 100.5", no change, installed new idler pulley, no change, new tensioner and pulley, Installed anther new belt, this time a 100" belt, still no change, Installed a new fan clutch and checked the alt. pwer steering, AC, all spin freely with no roughness to the feel. One thing I have noticed is the tensioner has a lot of fluctuation when running but all the other pulleys run true.  Have had this problem off and on for 5 years and 24,000 miles  I am at a loss?????????
Any suggestions??
Thanks in advance,
Bob

 

[ramblingvanman]

When does it squeal? AC on or off? In a turn? Under acceleration? All the time as soon as it starts? Are you sure it is belt squeal and not bearing or pump noise?

 

[highdesertranger]

yeah you have to isolate the squeal. a squeal is caused by belt slippage which is caused by,
1. excessive load on one of the accessories.
2. a bad tensioner or idler puller.
3. a bad belt.
4. contamination of the belt or one of the pulleys.
so first find out where the squeal is coming from. they we can look deeper. a very common squeal is from the alternator kicking out a ton of power. highdesertranger

 

[T.he I.nvisible M.an]

I just had that problem ...

Make sure no belt dressing has ever been used on it.

Check for any oil leakage that may have found its way to the belt.

In my case the "new" belt I bought was an after market belt and while the belt seemed to line up perfectly all the grooves and depth seemed ok this belt would squeal on acceleration and on startup every morning.

I used my engine serial number and went to our local Cummins Power which also sells parts and made a purchase of the factory original belt. The main difference I could see is that on the groove side the Cummins belt had all this fuzzy "hair" on it. The after market belt looked ok and was not worn or burned but it had a rubber surface and no "hair".

After installing the Cummins Factory Original belt I have not heard the squealing since that time.

T.I.M. 

Below is an image of what I saw on my belt (taken from the web). The top belt has no "fuzzies" and you can see the fuzzy on the bottom belt.

Click on the image or save it and blow it up to see what I am talking about.

 

[highdesertranger]

Tim brings up a good point. a lot of the belts they sell today are junk. highdesertranger

 

[BC Guy]

No just today. I had the same problem with a '72 318 back in '80.

 

[SternWake]

Get a nice metal straight edge and place it between all the different pulleys to find the one which is not in the same plane as the others.

My guess is the AC compressor.

 

[MikeRuth]

I just had that problem ...

Make sure no belt dressing has ever been used on it.

Check for any oil leakage that may have found its way to the belt.

In my case the "new" belt I bought was an after market belt and while the belt seemed to line up perfectly all the grooves and depth seemed ok this belt would squeal on acceleration and on startup every morning.

I used my engine serial number and went to our local Cummins Power which also sells parts and made a purchase of the factory original belt. The main difference I could see is that on the groove side the Cummins belt had all this fuzzy "hair" on it. The after market belt looked ok and was not worn or burned but it had a rubber surface and no "hair".

After installing the Cummins Factory Original belt I have not heard the squealing since that time.

T.I.M. 

Below is an image of what I saw on my belt (taken from the web). The top belt has no "fuzzies" and you can see the fuzzy on the bottom belt.

Click on the image or save it and blow it up to see what I am talking about.

looking at that photo, I would call the top one a "weather checked" as in old and in need of replacement now. 

Mike R

 

[ramblingvanman]

looking at that photo, I would call the top one a "weather checked" as in old and in need of replacement now. 

Mike R

Agreed. With all of those cracks I would replace it asap.

 

[SternWake]

That pic is not his belt but a pic he took from the net.

The OP will likely find one of the pulleys is not in the same plane as the others, or perhaps at a slight angle. This causes the wide serpentine belt to stretch more on one side compared to the other and a much smaller surface area is actually grabbing the pulleys with adequate pressure.

My AC compressor, now just a pulley, does not line up with my other pulleys it is at a slight angle. Mine has the Dual V belt. If I try and run both V belts, even if a matched set, one is too tight, one is too loose and the looser one will vibrate and make some horrible harmonics. I tried to straighten out the compressor but ran out of range. Improved but not fixed.

So I only run one V belt and replace it more often.

My alternator can cause it to squeal when damp and my battery is low and maxing out the alternator, but this is usually at 75+ amps.

Also, if the squealing has been going on for a while it is likely the pulleys are glazed. You can sprinkle some comet or Ajax powder on them with the engine running, and this usually stops the squealing, but only temporarily. Often the pulleys need to be cleaned with brake cleaner and a scotch brite pad. Belt dressing can really make a mess of things too.

 

[Tinman74]

Thanks all,
I will check out the pulley alignment, I have cleaned the pulleys but I will try again with brake cleaner, may even try the comet or ajax but as you say ,just a temporary fix. If I get to a dealer I will check out a new original equipment belt but I went to Chrysler dealer to buy a replacement air cleaner for my daily driver and it was a Chinese knock off made for Mopar.
To put this in a little more context, I took a 300 mile trip to Va early spring, the belt squealed the whole way down. Next morning when I went to check it out it would not squeal, drove around for 3 days and the whole way home without a sound. Last weekend I went to Ky. 750 mile round trip. not a sound.
Yesterday I went for a short drive it squealed. Today it doesn't???????
Bob

 

[ramblingvanman]

IMO, that make pulley misalignment less likely. I would look at the load you are putting on the engine. It sounds as if it MAY be load dependent. Look at the accessories you are using when it is squealing. Turn them off and see if the noise goes away. Is your belt tension manually adjustable? or is it a spring dependent adjuster? When it is squealing, try to watch the belt and see if the adjuster is "jumping".

 

[Tinman74]

IMO, that make pulley misalignment less likely. I would look at the load you are putting on the engine. It sounds as if it MAY be load dependent. Look at the accessories you are using when it is squealing. Turn them off and see if the noise goes away. Is your belt tension manually adjustable? or is it a spring dependent adjuster? When it is squealing, try to watch the belt and see if the adjuster is "jumping".

The tension adjuster seams to jump all the time even at idle. I think a bit too much .Any good reason for the fluctuation????

 

[Tinman74]

ramblingvan

It is a spring adjuster and it does jump even at idle. I think it fluctuates too much. Any Idea??
Bob

 

[ramblingvanman]

ramblingvan

It is a spring adjuster and it does jump even at idle. I  think it fluctuates too much. Any Idea??
Bob

If the truck was in front of me, I would use my stethoscope to listen to each pulley, tensioner, and idler to isolate the source. How handy are you? If you are mechanically inclined, and think you can safely do so, I would get a small piece of wooden rod or a long screwdriver(a mechanic's stethoscope would be ideal) and place it behind each pulley with the engine running. Put one ear on the end of the rod and plug your other ear. Listen to each one individually. The one that sounds worst/loudest is most likely the culprit. The tensioner could be losing tension, but if it felt tight when you replaced the belts, it is probably ok. I could not find a spec for the tensioner online. Apparently if the spring isn't broken they are considered "good".
 One other option. Did you install a cheap belt? If so, that could be it. You could try a goodyear gator back belt.

 

[T.he I.nvisible M.an]

Thanks all,
I will check out the pulley alignment, I have cleaned the pulleys but I will try again with brake cleaner, may even try the comet or ajax but as you say ,just a temporary fix. If I get to a dealer I will check out a new original equipment belt but I went  to Chrysler dealer to buy a replacement air cleaner for my daily driver and it was a Chinese knock off made for Mopar.
To put this in a little more context, I took a 300 mile trip to Va early spring, the belt squealed the whole way down. Next morning when I went to check it out it would not squeal, drove around for 3 days and the whole way home without a sound. Last weekend I went to Ky. 750 mile round trip. not a sound.
Yesterday I went for a short drive it squealed. Today it doesn't???????
Bob

Same EXACT symptom l had. (save your self some trouble and go get a new factory belt lol). I tried all the cleaning ideas I found on the net (no go). I also read that you should NEVER put ANYTHING on a serpentine belt. I tried brake cleaner ... didn't work. I took the belt off and scrubbed it down, cleaned all the pulleys (they had some rust on them but not much) still was squealing like yours, no rhyme or reason. Bought that nice (fuzzy) belt and the squeal was gone.



T.I.M.

 

[Tinman74]

rambling
I do have a stethoscope I carried with me, I could isolate some natural mechanical noise at each source but it did not pronounce or amplify the squeal.
Both belts were quality, I believe one was a Dayton not sure what the other one was but it too was a good belt.
TIM
I haven't had time to work with it yet, hopefully in the next few days. first I will check the alignment of the pulleys and then try to get to a dealer and check out the belts.
Thanks
Bob

 

[CTP]

I had a belt that slipped and squealed when weather was damp. I finally solved it by removing the spring tensioner and greased it inside and reinstalling it. Solved the problem

 

[Tinman74]

CTP

Today I checked the alignment of the pulleys and all looked good except the tensioner seamed to be cocked a bit so I put a very small shim under one of legs of the bracket. While I was doing that i did notice that the spring was a bit rusty. There is only a small opening that you can see the spring. How did you lube it and what type of lube did you use?
It isn't squealing at the present so I will just see what happens now.

 

[highdesertranger]

did you get a high quality tensioner when you replaced it? or just any ole one. highdesertranger