I have a 03 F250 V8 diesel 4 speed auto. I tow approx 3t with it and runs perfectly until i go up a hill/range. I'm experiencing overheating only when hauling up a multi kilometre steep incline, at no other time towing or not has the temperature gauge moved off where is always sits once warmed up. If i pull over when driving up the range (usually just before it gets to the red) and let it idle, it will cool down to normal again with in 10 - 15 minutes..

It has been backwards and forwards to the mechanic and has had the cooling system flushed, new thermostat, new radiator, new fan clutch, a trans cooler installed and is currently there having the water pump replaced ( even thou the mechanic didn't think that the old one looked bad ).

The mechanic can't make it hot in the shop nor has it failed any of the other tests they have done on the cooling system, pressure test etc

It is becoming a bit of a concern as i need a reliable truck to get me up hills regularly and the mechanic is running out of options if the new water pump doesn't fix the problem.

Just wondering if anyone has some other experiences or knowledge with such a problem?? Like i said doesn't miss a beat otherwise.

 

Hi Aussietruck, welcome to FTE!

Which engine does your truck have? There were two diesel engines in '03, the 6.0L and 7.3L.

 

Hi Tom,

Its the 7.3L diesel engine.

 

So do you ever hit the clutch fan engage when the temp guage goes past the half way mark?

 

I can barely hear the fan let alone it engaging when travelling up the range, that was why we had the fan clutch replaced. Is there a manual switch or some way of engaging the fan clutch when you want?

I thought it was more of an automatic thing the truck did as it needed to...

 

Classic sign of a water pump failure on the 7.3L

 

Thanks Curtis, that gives me some hope. Its in the shop at the moment having a new one fitted so fingers crossed it fixes the problem.

Just don't know where to go from here if it doesn't !!!

 

The only other thing I can think of is the fan shroud.


Years ago we had a truck that was bought used. It would overheat because of missing shroud.


So how about yours?

 

The clue here is the word "Aussie" - I think the 7.3L was available down under until 2006, but I can't remember.

How is the overheating showing itself? Are you using a Engine Coolant Temperature PID with a scan tool/gauge, or the gauge on the dash? If you are using the ECT PID with an automatic, you'll want to stop doing that - it's lying. The ECT PID doesn't work on this engine with an automatic transmission.

If you're not hearing the fan sound like you're on a takeoff run in a Roulettes PC-9 while the engine is actually overheating, that's a bad fan clutch.

 

Mate if you can barely hear the fan kick in that don't sound right to me? When both my trucks the 99 250 and my 350 dually pulled my fiver up a grade and the fan would kick in it was loud and sounded like a jet engine under the hood aka bonnet!

Smokie

 

x2 on Pocket and Smokiesman...

 

Hey Senix, I'm not sure on the shroud but i will have a look, Thanks for the tip.

 

Hey mate, we are just running off the dash temp gauge, not a super mechanical fella ha ha ha

The fan definitely doesn't sound like we are about to take off and its brand new!!! I believe they work off the water pump so I'm hoping that replacing the water pump may fix that issue as well!! I can here the fan when i first start the engine cold but it still doesn't roar..

 

Also make sure it has the correct thermostat. 2 versions are available for the 7.3, one long and one short. If I recall correctly the short version is for the pre 1999 7.3 and the long is for the 1999 and later. Sorry not to post more info but if you do a search on thermostats in this forum you should come up with some good hits including measurements. I'm short on time right now or I would do it myself.

 

Also..../ don't put to much faith in the dash gauge. If you can get your hands on an infrared thermometer try taking a reading off the thermostat housing when the gauge shows you are overheating. My guess for a good operating temp at the top of a hill pulling a 3t trailer on the wrong side of the road would be 220ish F aka 104*C to 240f or 115C if you are near coober pedy in January ( cause it's hot there in January).