SewperDrewper
Full Access Member
So I have posted bunch in the IDI forums since I also own a '91 F350 4x4 with a 7.3l IDI and E4OD Tranny. Switched professions and needed a truck with a few less hiccups and better fuel mileage. I just purchased a used 2004 F350 with the 6.0l Powerstroke and the Auto tranny. Drove it sorta hard during the test drive with the AC on full blast and didn't have any issues, but only drove it around for about 10 minutes. As soon as I filled it up (Bye Bye $100) I got on the freeway and within 10 minutes it was getting hot. Started watching closely and within another 5 minutes, check gauges light came on so I threw the heater on full blast trying to cool it off. Funny thing was, temp started to very slowly drop, and within about another 5 minutes, warning light went off, but it was still a little warmer than I'm happy with, but the Air didn't get hot for about 15 minutes. Took it down to my little hole in the wall mechanic and he put it under a block test, which it halfway failed. It blew the fluid out of the testing device, but he couldn't get it to change colors. The previous owner has replaced the thermostat within the last 6 months, so I'm gunna go ahead and just rule that out. Any ideas what it might be? Water Pump?! truck has 115k miles on it right now.