1998 3.9 dakota sport 4x4

so a few weeks ago my belt developed a slight chirp so i used some belt dressing to quiet it down, needless to say it only made the issue worse until i decided to replace the belt. i bought a new belt 88.5 inches (because i have it routed under my frozen a/c compressor) and found out that i couldn't get the belt to fit on. i went and purchased a 90 inch belt and it fit with no issue but with the same chirp. i took it off and cleaned all the old belt dressing from the pulleys and put a new 90 in. belt on. same noise. i'm really at a loss to figure it out. it will squeal at start up and quiet after awhile and then it will only make noise under load. could it be that the belt is to long? a bad tensioner? the noise is driving me crazy and any advice will help. also when buying the 90 inch i cut and measured the old belt and it was around 90. could that have been the issue all along? a worn out belt replaced by one the wrong size?

 

Check the belt tensioner. Make sure it is spinning freely and that the tension on the belt is correct.

Since you are bypassing the compressor, the belt may be to long for the tensioner to maintain the correct tension.

Is it the compressor that's gone or the clutch bearing? If it's the compressor itself, disconnect the electrical connector on the clutch and route the belt around it again.

 

The tensioner is most likely causing your problem. While you are in there you should replace the idler pulley both are cheap to replace

 

its the bearing on the compressor, it was like that when i got the truck. when i went to buy the new belt i told the guy at autozone i needed the belt for without a/c and it came up as 88.5 in. which seemed to short with the tensioner pulled in all the way. but i think that if thats the size called for and i went 1 1/2 in. bigger, maybe thats my noise. i know my friend has a spare tensioner around maybe i'll try swapping it out. should i try a smaller belt?

 

Here you go scroll to the bottom of the page. https://dodgeforum.com/forum/2nd-gen...tchin-a-c.html

 

ok, so replaced the tensioner and idler pulley tonight and no change. i'm totally lost with what to do next. i'm going to switch up to a 90.5 inch belt to see if that makes a difference. any and all ideas are welcome, cause i really have run out of them.

 

Hows all your pulleys and your fan clutch? If your thinking why fan clutch ill tell you why. My buddy had a jeep and could not figure out why his belt was squealing. Everytime you sprayed belt dressing on the belt it would quiet down for a couple min. After weeks with dealing with it and it getting worse he noticed his temp gauge was reading higher than normal almost in the red until you got moving. He replaced the clutch on the fan and that cured his squealing problem. You could have the same problem only its not constant yet.

 

Have you chnged your power steering pump out lately? Here's why I ask. I bought my 2003 Dakota with the 3.9 in Feb. of this year. The only thing wrong with it when I bought was a slight squeal from the belt. I told the dealer he would have to fix it if I bought the truck. I just guessed it needed a new belt even though he said it was new. He also said he had changed the PS pump and alternator. It took him a few days to get it into the shop so I sprayed some belt dressing on the belt and it made it worse. To make the story short, the squeal came from the pulley on the PS pump being out a fraction of an inch. I mean just a 1/4 turn on the pulley puller to line it up. If he went the wrong way it was worse. Once he backed it back out it purred like a kitten and not a single problem since.