I've just picked up what appears to be an accessory noise under the hood and thought I would ask for some pointers. My truck is a 1999 7.3 2WD with 201,000 miles. I think the bearing in the idler pulley under the AC is the culprit. How about the other fixed pulley just to the right of the AC if you are looking at the engine? It's almost centered. The only reason I think its the idler is the chirp occurs while it is bouncing at idle. Its most noisy at 1,500 RPM. While I have things apart, I'm going to replace the belt and any other items that are easy to get to. If you have any suggestions, I'd appreciate them.
Thanks,
Todd

 

When you replace your belt, you are going to have to pull the upper radiator hose. Go to the parts store and get an upper coolant hose for a double alternator set-up. The new hose will not snake through the belt.

If you havent replaced the coolant lately now is a good time (since you have to remove the hose). Make sure you get the right amount of (DCA)additive to mix with the new coolant. Napa has all of what you need, including the pulleys. If you have green coolant in it now, use only green when you do a flush. The yellow for the newer trucks will not work in the older PSD's.

Waterpump and thermostat are other items to consider replacing. A 210 degree thermostat and thermostate housingi from dieselsite are an excellent upgrade for your truck.

Do a good visual inspection of the underneath portion of you waterpump. Take a flashlight and shine it underneath wher the weep hole is located. If there are white deposits forming around it.....your waterpump is on its way out. replace it while you are doing the belt/idler change. Most waterpumps will start leaking at a slow rate and the coolant will evaporate befor it gets a chance to hit the ground. Thus the white deposits are left behind.

Thats all I can think of for now. More users may chime in on stuff to consider while your in the area.

 

Maybe you can spray some wd-40 in the center of the pulley to make sure it is that? Just don't want to get much on your belt.

 

You only have to remove the hose if you are going to replace the belt (which is recomended if you have never done that) I bought one of those hoses when I did my water pump, and would not fit right. It was the napa one so if you do that don't buy the that one.

 

Replace the idler and tensioner. They both will wear out. I did mine at about 2/3 of the mileage you're at and they showed wear in the bearings.

 

I got my around the belt hose a napa and it fit fine.

 

Mine too. They had both hoses, but the one that goes around the belt was listed as the "preferred" part.

 

Not a bad idea, my tensioner expolded one morning on my way to work. It sounded like a gun shot, then I saw the idler wheel bouncing down the road behind me. On its way out, it took a chunk out of the fan and stripped the wire that runs to the cps. Not a good way to start the day.

 

I hear ya, I had the same thing happen too me, luckily mine didn't take out anything, just went flying across the road. I'd suggest like some of the other's have said, replace the tensioner and pully.

 

I'm finally getting around to this. Does anyone ever replace the bearings on the pulley's instead of the whole unit? Seems like the bearing is the culprite. They all have bolts on the pulley. Was considering just replacing the bearings.
Thanks in advance.
Todd

 

I think that I may have this starting up too, just kinda suddenly at 74,000 mi.


It only really happens when idling- not when under power-- does this seem to be the same deal?

Also, for those of you whove done this before, can you possibly throw out some cost estimates, part numbers, pics, etc?

any info would be appreciated-

(PS, not trying to hijack the OP's post, just 'tagging along' as I seem to have the same symptoms)

 

The whole unit will stock to get a little ****-eyed and not track straight regardless of the bearings.