Ford E450 7.3l diesel engine is making some weird noises

[imfromatlanta]

Hello all! I’m trying to get some advice on my bus. It’s a 2000 E450 7.3l diesel engine with over 200k miles on it (the actual mileage is unknown). I’ve been driving it for a while with no real issues. Mid August, it drove from California to New York with no problems! Then, it sat for about a month (I know, that’s my bad). I went to start it up, drove about a mile, and then started to notice a weird sound.



It sounds like something mechanical, almost like gears not grinding correctly. There is a squeak, which made me think there was an issue with the fan belt; but the squeak isn’t constant. Both the mechanical sound and the squeak only happens about once every 30 seconds, but not constantly.


I made a video to try and capture the sound: https://youtu.be/ro5EgEO5voQ


I’m not the most car savvy, but I’m learning! Any help would be greatly appreciated!

 

[Johnny Mullet]

Sounds to be in the belt drive somewhere. If you remove the belt and start it, does the noise go away? If so you got a bad pulley or component somewhere. Hand spin each pullet with the belt off and engine off to find it.

 

[roach711]

I'd agree that it sounds bearing related. Several 7.3L owners here have had serpentine belt tensioner pulleys seize and spin off while on the road.



To untension the belt, take a 1/2" breaker bar and insert the square drive into the front of the tensioner then pull like hell to the passenger side while sliding the belt off one of the pulleys. Once the belt is off you can check the bearings on all that stuff that the belt runs. Take a picture of the belt routing before unshipping it.

 

[imfromatlanta]

I went ahead and took the belt off. The tensioner was looking a little worse for wear, so I went ahead and replaced it. Put a new belt back on, hoping that would solve the issue. There isn't so much a squeak anymore, and generally overall it sounds better, but I'm still getting this occasional clunking sound. It happens while the bus is idling (and driving), it happens every 30 seconds to a minute, and it definitely sounds like a mechanical clunk rather than a constant knocking or tapping

 

[brokedown-SKO]

If it does it at idle, I think you're gonna end up with a stethoscope to find the source of the noise.

Harbor freight has one for under $4. https://www.harborfreight.com/Mechanics-Stethoscope-63691.html
You can use a 20% coupon on it to save almost a buck. http://www.hfqpdb.com/coupons/20_percent_off_1568231279.4759.png
Then since you've made a purchase, get a free multimeter with this coupon. http://www.hfqpdb.com/coupons/11_FREE_7_FUNCTION_DIGITAL_MULTIMETER_1567917249.0792.jpg

There are a few things that might clunk on their own on a warmed up, running engine. The fan clutch for one, at idle an engaged fan won't make a ton of whooshing noise but it will engage/disengage with a thunk. Your thermostat might thunk when going between open and closed. Does your noise happen when the engine is cold too?

Maybe you can make a new video now that the squeak/squeal is gone, that's honestly all I could pick out of the first video.

 

[imfromatlanta]

So, I went to make a new video... Started the engine, started filming, and then immediately saw white smoke out of the top and green coolant spewing from the bottom
The only bright side is that now i can see a physical issue - the radiator fan is slightly slanted and the coolant is coming out of the fan. I'm currently draining the coolant so I can take out the radiator and have a better look at the fan.

I'm still not entirely sure what the main issue is, but hopefully I'll have a better idea once I get in there

 

[Johnny Mullet]

Water pump or fan clutch issue. I suspect the water pump failed.