Stuck in Commiefornia...
Join Date: Dec 2008
Location: Clearfield, Utah
Thanked 447 Times in 315 Posts
Have you verified the actual temperature? A bad temperature sending unit or a short in the wiring can pin the gauge hot. A thermostat stuck open will overheat under loads and run cold at cruise speeds especially going downhill, on the other hand a thermostat stuck shut will get the engine hot and keep it that way. Water pumps can fail without leaking, I've seen the impeller come off of the shaft or spin on the shaft. Radiators on these trucks are not usually a problem but the coolant bottle can be. If your coolant bottle is cracked the system won't hold pressure and without pressure the coolant will begin to boil at just over the temperature water would boil at without the added pressure the cooling system is designed to operate with. And of course don't neglect the coolant bottle cap, they can and do go bad and when they do they can cause overheating for the same reason as a cracked coolant bottle.
Verify with a mechanical or infrared gauge that the truck is actually overheating or getting as hot as you think it is. To test the water pump, get the truck hot and turn on the heater full blast. If the heater starts out rocket hot and then cools off you have a coolant flow issue and I would suggest replace the thermostat and water pump, both have issues, and both have been replaced on my truck in the past two years.
The Current Truck (Oct-2013 to Present):
1999 (Early) F-350 Lariat, CCLB, SRW, Black/Tan
7.3L Powerstroke, 4R100, 4x4, 3.73, 37x13.50-18s, '05 Axle Swap, 6" Fabtech lift, GTP38 "D66" turbo upgrade, SCT 4-position chip with custom tuning by me, Straight Piped 4" down pipe through 5" dual stacks, N-Fab full length triple steps, Pro-Tech cab guard and tool box, louvered 5th wheel gate, Hella 500 Fog and Driving lamps, much more to come...
The one I'll miss, (Mar-2009 to Jan-2014):
2000 Excursion XLT 4x4
6.8L V-10, 4R100, 4.30, 285/75-18, 271whp / 388wtq
The one I won't, (Jul-2005 to Sep-2012):
2005 F-350 XLT, CCLB, SRW, 4x4 FX4
6.0L PSD, ZF-6S650, 3.73, 35x12.5-18, 4.5" Lift
Last edited by IdahoF350; 09-04-2017 at 05:48 PM.