HELP!!! belts/pulleys/something making awful racket

Hey guys,

Merry Christmas, hope everyone is enjoying the holidays! I would be if my truck wasn't running like shit... I have a problem and need some help, so if anyone knows anything, help would be greatly appreciated! A few days ago my check engine light came on. Couldn't do anything about cuz I was in the field working. As I was driving home for Christmas last night, the light went out. Hmm I thought. Truck seemed like it was running fine, no noises, no nothing. So went to start it this morning and started fine, Let it warm up for a while (cuz it's about -25 Celsius here) then I started driving it around and every couple minutes I'd hear an awful noise, sounded like there was a playing card hitting the fan. For a little while it was off and on then it stopped. I parked it for a bit then went out and started it and the noise would not stop. Shut the truck off, opened the hood and everything seems fine. So I got my dad to take a look at it (a little more mechanically inclined than I am). I started it up and he said it appears the tension pulley is wobbling and gets hot. So, to clarify things, it's making like a horrible rattling noise almost like a card hitting the fan. Has anyone ever had a similar problem? Could it be that pulley? All help is appreciated! I'm off for 3 days...of course the days a shop isn't open and going back to work the 27th. Some help is better than none! Thanks guys!

 

Sounds like you need a tensioner ASAP. Would be nice to see what the code was for the CEL.

 

This happened to me also. I took my radiator fan and shroud out while I was replacing my drive belt. It turned out my radiator fan was hitting on the bottom of my shroud. It actually wore a hole through it. So I just cut that section of the shroud out and I havent heard it since

 

I'd start with a new belt.

 

That's a good idea, and when you have the old belt off you can spin all the pulleys and fan by hand to check for problems.

 

I had all my idlers crap out between 118K-120K km on my 08 TRDsport. I pulled my skid plate and dealt with the belt and pulleys from underneath. I think OEM is $100 for belt or idler and $200 for the tensioner assembly including the idler (changing that rig is a small PITA). I hope it's an easy fix. Merry Christmas!

 

But the belt looks fine and we tried wiggling the pulleys and didn't seem like any bearings were gone.

 

Check to make sure your motor mounts look good, is the fan hitting the shroud? Pull off your belt and spin every pulley by hand and listen for noises or pulleys that don't seem to turn well.

 

hope its just your idler pulley, and not your oil pump that sounds the same way, known problem.

 

You need to take the belt off to check the pulleys and such if you haven't already. They're under a lot of tension and can't be checked with the belt on.

Like Max just suggested, you gotta check every possible cause step by step. Sounds like you have a couple days to do that and will be ready to get parts if needed when the stores open back up.

ETA: If your Dad thinks there is a problem with the tensioner I'm going to go with that. I'm guessing he's probably about my age too.

 

Fan hitting shroud means bad bearing or broken engine mount.
Good news is, on the 4.0, the fan is on an idler, not the water pump.
Idlers and tensioner idler are common failures. Remember, it's spinning above engine RPM and gets no active lubrication... just sealed bearings.
Salt and offroad take their toll.

 

Haha. Thanks. Buuuuutt.. I can't do that. I don't know how and I have no tools to do so.. just want some ideas to bring to a mechanic.

 

Put a breaker bar on the tensioner bolt and give it a push opposite the way it's pressing on the belt.
The belt will loosen up and you can feel each pulley for wobble while someone else holds the tension off the belt.

 

With all the tension on the belt you will not see anything wiggle until you take the belt off.

 

Any missing cats or animals--they love warm engines!
Run the engine to find exactly where the noise is originating.
Are the belts squealing--fan hitting something.
had an idler bearing go bad--squealed LOUD--it would freeze after warming up-BTW-on my 91 pickup.

 

I have a mechanic that I use when I don't feel like working on things. If yours is anything like mine, he'll have no problem finding the problem by your description.

Have a Merry Christmas and Happy New Year!