we are new to the diesel world, so please excuse my terminology. We recently acquired a 2008 F350 6.4 liter powerstroke. The truck is making a noise that we can not pin point. It sounds a lot like a bad bearing in and idler/tensioner pulley. We went and purchased the belt and pullies. The noise is still there. (we started it for a few seconds before the belt was installed, and the noise was still there.) the noise sounds like it is coming for the right side, however I can not verify it. Any advise/pointers would be greatly appreciated

 

Check for exhaust leaks at the manifolds, broken manifold bolts.

 

Okay, We are in the process of drilling one out as we speak and it is on the right side. I will keep you informed. Thank you

 

There are two belts, each having it’s own tensioner pulley.

 

We replaced the main serpentine belt for the AC/power steering/water pump..... we did not see a second belt. Is it buried somewhere we need to dig to?

 

Yep. The alternator belt. But if you found the broken manifold bolts, that's likely what you're hearing. I bet the noise is loud when you're on the gas, and it comes and goes. That's from the heat swelling the manifolds up a little and closing the gap. In the mornings I bet it's real loud from the turbos increasing the back pressure to speed up the warming up of the truck.

 

There is a fwd belt and tensioner (outer) and an aft belt and tensioner (inner). It sounds like you
just replaced the fwd (outer). I think the aft (inner) only runs the AC compressor.

 

You are correct we replaced the outer only. How do we get to the inner tensioner? We drilled and tapped out the exhaust manifold bolt and it now tight noise is still there.

 

I believe you have to remove the inner fender and the outer belt. Jacking the truck up and removing the tire may help, or perhaps just turning it to the right may give you room. The inner fender is plastic and held in place with about a half dozen screws. Removal of that is easy.

 

You probably had that inner fender out when you repaired the manifold. Check the bolt that holds the A/C clutch on. When we did the front engine cover on my truck, we noticed that the bolt holding the clutch on was almost out.

 

Thank you---We are ordering parts now and Ill keep you informed

 

You'll need to remove the outer belt for sure. You'll also need to remove one of the lower fan stator/housing bolts as it goes through the middle of the a/c belt. I also believe that the tensioner, or one of the idler pulleys for the outer belt has to be removed as well in order to allow inner tensioner to come off. It's been a couple years since I did mine.....but I recall one of them being in the way. I did mine without removing the wheel well liner. Did them from the top....removed the top portion of the fan shroud to allow access. Both belts and all tensioners and pulleys can be accessed either from above or below.

 

Not a fun job that’s for sure. I just did mine when I didnthe radiator and water pump. Easy as pie then but looking at it all together looks like a major pain. Hence why everything on the front of the motor was replaced when the radiator came out.

 

I replaced my outer serpentine belt about a year ago, but didn't do the single alternator belt and tensioner because it was very cold and raining, and I thought I had to remove a motor mount. Now I think it's time because of the grumbling and growling noises. I have 125k miles and 5.2k hrs on the clock of the '08 F-350 6.4 diesel. How difficult of a job would it be to just replace the alternator belt and tensioner?

 

Not a bad job. Access on top, bottom, and passenger side wheel well by removing liner.