f 250 7.3L help please - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

JOSEAN4700 · 07-10-2011, 08:28

i recently bought a 2001 f 250 7.3L diesel truck love it but its been working with the temp too high ( almost to the red part ) i noticed that when i go too fast the temp goes up fast and when i slow down the gauge goes down, a lot of people tells me its the fan clutch that gets slow down by the wind could anyone please help me and thank you so much

tdpower · 07-10-2011, 12:04

Probably your fan clutch. You should hear it kick on when the temperature rises. You should also make sure the radiator is not filled with dirt between the fins. A new thermostat would also be a good idea. The bolts holding the thermostat housing can be a pain to get off. Most replace the housing and bolts. I think dieselsite carries the upgraded housing.

JOSEAN4700 · 07-12-2011, 16:00

i already replaced the thermostat still working real high on temperature

PatriotHauling · 08-08-2011, 22:28

Its not your clutch fan. If your fan is turning on then there is an underlying problem. The clutch fan will not turn on until the temps are elevated past a normal operating temperature. Look for major boost leaks, or exhaust leaks.

Next check your coolant. Most people dont check it. In these engines the coolant must be maintained with an additive (like a swimming pool) or replaced with ELC coolant. If your coolant is green then you have original coolant that is supposed to be maintained.

**R.S.LOGAN** · 08-09-2011, 03:12

Seen that happen with partially choked radiators , might be worthwhile flushing out cooling system and see if any improvement .We also get some cars over here with water pump impeller failures / wear causing this , but dont think this would apply in your case .

rved2 · 03-23-2012, 08:46

try to spin your fan if it turns more than 5 times it is the clutch. that is the way old timers do it.

**360ci** · 03-31-2012, 18:48

If the wastegate isn't letting out the additional boost, the engine will carry the burden and overheat.

If the coolant has been in the truck for 6 years or longer, regardless of miles, flush it and replace with fresh coolant mix. Diesels are iron blocks in almost all cases (some newer ones use thick aluminum pistons), and iron rusts; even more so if you only use the truck for short trips. Remove the coolant/rad cap when the engine is cold. If you see any white goop, or small chunky crap around the edge, you need a coolant flush. A flush can also dislodge built up particles stuck in passageways that help cool the engine. To elaborate more on Logan's post, the water pump impeller (fins) can rust and deteriorate lowering proper coolant flow throughout the block.

I'd advise this as a last resort, but if winter weather isn't an issue you can change from a 195F thermostat to a 185F that should keep temperatures in check.

If you have yet to get the transmission serviced, do it once you manage the engine temperature problem. I mention it only because heat is the ultimate enemy to a transmission. An engine that is consistently close to running in the red also warms up the transmission, even more so if you tow/haul/off road the machine.