Not sure but I need something bigger, might be going over to the dark side...(Chevy) those 6.0 gas engines caught my eye. I bought a toy hauler that I thought my f1 would be fine with but it wasn't that was the reason for the sale.

 

 

I had a similar problem. It's tough narrowing these sequels down. My F-150 XLT V6 4.2L had 170,000 miles on it. I was sure it was the water pump - turned out to be a serpentine belt that looked good but had "grown" 2" over the years. I also replaced the belt tensioner with the belt. How I found it? Took the belt off, went to AutoZone, and put it up to the new belt with exact same part number. Everyone was pretty surprised at the "expansion". I changed the tensioner also - probably original. I am not saying this is your problem, just one I could check easily without costing any money - until I knew it was the belt.

 

The water pump was his problem..... and he sold the truck.

 

Thanks I actually have a super duty, 05 6.0 powerstroke... pile o junk! Constantly needs working on! That's why I've been debating the 6.0 ls 2500's

 

Thanks! And yeah I've seen that happen. I used a stethoscope and found it was the water pump. I actually sold the truck a few days ago as well to get something bigger