overheating powerstroke 7.3

[SCDEALER]

new to this forum, and hate for first post to be a problem, but mabe as time goes on i can give some assistance rather than needing it...

i have just bought my fourth 7.3. first was a 88 that i added a banks turbo to, second was a early 99 250 with 7.3, next a late 99 350 7.3 had 340k and still ran and pulled great with very little blowby, and finally i upgraded to a 4 door 2002 with a 7.3 190k.

problem: truck runs great, pulling single car trailer..6k lbs no problem. when i put my 3 car behind it loaded... 13k lbs, it will pull fine at 75 flat or a slight incline, but when i hit a hill and have to lay into it a little it will start heating up to the 3/4 on the heat and i think it would keep climbing if i let it. my other two 99's never would budge the heat guage at any time.

the engine oil temp runs around 230 pulling and when it starts to overheat it will climb over 245. as soon as i top the hill it cools back down fairly quickly.

i replaced the clutch fan bc i dont hear this one locking in like my last 99. but it had a vinal floor and this one has carpet, i think that is the difference. i am pretty sure i can hear it comming and going not positive. the new fan is a oem ford so it should be good. i am thinking thermostate next...mabe i should have started with that but like i said on my other truck the clutch fan was very obvious when it engaged and this one is not.

any suggestions would be appreciated.

Fletcher

[GoFastPadre]

It could be the thermostat. I would suggest a flush and fill on the coolant system. If that does'nt help I think I would look into the water pump itself and the hoses too one my be colapsing on you. Just my thoughts

[SCDEALER]

and does exactly same... when showing 3/4 to the hot line... the oil temp is 250 and the trans temp is showing 212... this doesent sound super hot to me, what are they suppos to be when towing 10k lbs. could i have a sending unit on the temp bad?

Fletcher

[2005F250]

You could have a bad radiator. Get the truck to operating temp and then feel the radiator with the palm of your hand and if there are any spots that are hotter or colder than others then you probably have a bad radiator. Or your water pump may be going out.

[RadarRider]

Originally Posted by SCDEALER

and does exactly same... when showing 3/4 to the hot line... the oil temp is 250 and the trans temp is showing 212... this doesent sound super hot to me, what are they suppos to be when towing 10k lbs. could i have a sending unit on the temp bad?

Fletcher

Have you tried flushing your cooling system? Is your anti-freeze sludgy? Also, your trans temp sounds like it's @ it's threshold. It definitely sounds like you have a blockage somewhere if you have insufficient cooling when your water's @ the correct level. Since you're towing you should look into a 6.0 tranny cooler. That one cooler is bigger than the 2 you have on your 7.3 & it's easy to install. A few last things: how the condition of your radiator, trans cooler, & water pump? When's the last time the oil's been changed?

[SCDEALER]

Thanks for the responses... the coolant looks brand new, when i pulled the theromostate neck off their was some crosion built up on the neck itself, but i think it is just cheep pot metal stuff. the oil is around 4500k and i usually change at 5k, looks good. i am leaning tward pulling the radiator out to have it checked...though i dont think this is it. the heater is hot and works great, woldnt that get clogged up if i had a sludging problem with the coolant? i have never been a fan of a chemical flush,,,seems to me to always cause leaks to develope. i hate to be a parts swapper, but i dont know what else to do, the only things left are the radiator and the waterpump, and the pump feels tight and is not leaking and does not make any noise.

my old 99 clutch fan would sound like a tornado locking in and out on the highway... this one i can hear but it is definatly not the same noise level...any comments on that?

i dont feel i have a head gasket problem, bc it doesent push any coolant out, and the coolant dosent look contaminated at all.

thanks Fletcher

[SCDEALER]

just wanted to give a update... i have flushed the cooling syestem 3 times over the last 2 weeks, and each time the fresh water turned black as could be. no particles or solid, jus very dark water. i am on the 5 or 6 drain and refil with water and i think it is clearing up.

i have hooked up similar loads that caused it to run hot before and pushed it very hard and have had no more overheating trouble.

with that said i feel that this was the problem... and i am asking myself if i should pull the radiator and have it checked or is the chemical flush adequate??

Thanks for all the input during this problem. i have been reading about coolant filters on deisel motors. is this a problem with them. as i said before the coolant looked like brand new when it came out, but obvioulsy it had a problem.

one other question on this subject if a coolant syestem is a closed syestem... how does it get contaminated?

Thanks Fletcher

[RadarRider]

Originally Posted by SCDEALER

Thanks for all the input during this problem. i have been reading about coolant filters on deisel motors. is this a problem with them. as i said before the coolant looked like brand new when it came out, but obvioulsy it had a problem.

one other question on this subject if a coolant syestem is a closed syestem... how does it get contaminated?

Thanks Fletcher

A coolant filter is an excellent idea for keeping your cooling system clean. From what I've read, the contamination comes from casting shavings that are trapped in the cooling system during engine assembly accumulates together over time. Those castings remain there even after the engine's been assembled & the coolant system filled. Our cooling systems are optimal, but this casting sludge is the only fatal flaw. I'm not 100% sure this sludge would cause your cooling system to deteriorate the way your's has, so I'm guessing it hasn't been serviced in a while. Make sure that the black substance in the water isn't oil. This would give you a sign you might have another problem.

[SCDEALER]

its not oil, pretty sure of that... like i say the overheating problem is gone...just waititn for all the crap to clear out before i refill with coolant.

was wondering weither it would be worth splitting the radiator to have it rodded out, or weither the chemical flush has don a good enough job.

[RadarRider]

Originally Posted by SCDEALER

its not oil, pretty sure of that... like i say the overheating problem is gone...just waititn for all the crap to clear out before i refill with coolant.

was wondering weither it would be worth splitting the radiator to have it rodded out, or weither the chemical flush has don a good enough job.

How's the condition of the core on the rad itself? If it's badly damaged, I'd just have it replaced(kinda expensive, though)or recored. If your rad is OK, then do like you said & just flush it until the coolant's nice & clean. Make sure, also, your thermostat isn't caked with any of this crap or you'll have some more problems down the road.