I have a 1999 F250 7.3 LDiesel 2WD with Automatic trans... 63,000 miles. In the past week I have started hearing a noise that I would describe as a metal on metal or growl. Sounds like its coming from the center of the truck but hard to tell. The noise is most noticeable between 30 and 45 Mph. And seems to be loudest when you give it just a little gas and put it under a slight load. But you can still hear it when coasting. When you come to a stop it goes away.

I have had two mechanics look at it and test drive it. The first guy really could not say but was pretty sure it was not the Turbo...He wants to put it on the rack but I had to make an appointment (Jan 11 2008) Ha...The second guy was thinking it could be coming from the Turbo but was not sure but they dont do Turbos?

I was thinking if its the turbo why would it stop so suddenly when the truck comes to a stop. I know its hard to diagnose this kind of stuff but was just wondering if anyone has had any similar experience?

Doug

 

If it was the turbo, it would be making noise constantly. What body style do you have? The longer trucks have a carrier bearing due to the two piece drive shaft. That could be the problem.

 

Thats really a good point. I do have the long bed and did not think of that. Climbed under and looked and I do have the mid bearing? Anyway to check that?

Doug

 

You could remove the two bolts holding it up and lower the drive shaft a little. Then rotate it around and see if it feels smooth or harsh. Careful though, if the slip joint is greased properly, that driveshaft will drop down on you. Mine wasnt the first time and I could hang on it and it wouldnt slide.

 

I checked my service manual and it doesnt list a way to check it. The only thing you need to be sure of is that the holder for the bearing goes on the right way. It has a front and back.

 

Well.... Not necessarily. My buddy's CTD had a intermittent noise that ended up being the turbo. Check the side-to-side & in & out play by pulling the intake tube to the turbo and try moving it up & down & in & out. A very slight movement is okay, but not much. And of course, it shouldn't TOUCH the side if you move it.

 

Does that year have the torque converter that goes NOISY after a while???

 

That sounds like rocks in a tin can, right?

 

Can you duplicate the noise in park or neutral? Try revving the engine and holding it at different RPM's. That will help eliminate some parts. You might also try shifting into neutral while rolling at a speed that makes noise to see if the noise continues.

Just trying to help narrow it down some.

 

We tried raising the rpm's and listening to the various engine parts with a stethoscope but could not specifically identifiy a problem. We thought we could hear something but nothing jumped out. Nothing like what we hear when going down the road between 30 and 45 mph...
Doug

 

My early 99 did that, but it was only noticeable at idle. BTW Ford recalled it I think.

 

Yep, has a tin can sounding torque conveter but that noise is separate from the one I am hearing now...

Doug

 

So. you don't hear anything at idle other than the loud TC? I've had a lot of front end parts replaced on my truck, so if the sound doesn't change when going 30 and shifting into neutral, I'm guessing hubs/bearing/axle joints. If It's other than those I don't know. Someone with more knowledge on this site will chime in.

 

Have you tried shifting to another gear when the sound starts up? If its something in the driveline, the sound wont go away when you change gears.

 

Have you checked the turbo wheel for play yet?