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tltruckparts 02-14-2010 04:33 PM

engine running hot, but not overheating! help
 
well ive been fighting this hot running problem for a while now. it has a brand new heater core, radiator, thermostat, all new hoses and its still running hot

i just even put an electric fan from a taurus in there to help it and its still happening. before when i had the mechanical clutch fan, it would rise in temp at idle but would cool down while driving, now with the more powerful fan, it doesnt heat up past normal at idle, only when driving. but when it heats up hotter, the fan does just enough to keep it where its at and not continue to climb.

i have good flow everywhere, pressure is holding up good on all hoses and theyre all hot from the hot water. i have a brand new headgasket and that didnt fix it either and it shows no signs of a cracked head or block or bad headgasket as there is no oil in the water or exhaust.

it doesnt tach out to the red part of the gauge, but it gets up to about 235 or 240 and will stay there. it makes me nervous and i dont like it. anyone have any ideas?

ArizonaRedneck 02-14-2010 05:49 PM

your radiator doesnt have pluggage problems does it :humm:

tltruckparts 02-14-2010 09:42 PM

i dont believe it does. i just bought two things of radiator flush im going to try it in the morning. i dont even think thats my problem though

captain_stabbin 02-14-2010 10:18 PM

maybe bad temp gauge?/ i've seen this cause problems before!! good luck

tltruckparts 02-14-2010 10:32 PM

pretty sure its boiling pretty good. i got a brand new sending unit for the gauge in there as well. i only have water in there there is no coolant would that cause this problem? i havent put coolant in yet because at 20 bucks a fill up it gets expensive when i keep havin to take stuff apart

Diesel Nut 02-15-2010 10:10 AM

First and most obvious question, does the radiator cap work properly? If its even a question then go get a new one. They are like $10. If its not holding pressure you will boil the water.

blkjack 02-15-2010 10:41 AM


Originally Posted by Diesel Nut (Post 495325)
First and most obvious question, does the radiator cap work properly? If its even a question then go get a new one. They are like $10. If its not holding pressure you will boil the water.

X2 and yea just straight water will cause the temps to go high as well hence antifreeze/coolant it mixes 50/50 so you get the boiling point down and also the freezing point down as well. but I would check the rad cap first and then drain and flush the system and then do the 50/50 mix and see what happens from there.

tltruckparts 02-16-2010 12:35 AM


Originally Posted by blkjack (Post 495350)
X2 and yea just straight water will cause the temps to go high as well hence antifreeze/coolant it mixes 50/50 so you get the boiling point down and also the freezing point down as well. but I would check the rad cap first and then drain and flush the system and then do the 50/50 mix and see what happens from there.

i know the radiator cap is good the first one was put so i put a new one on. im going to run some flush through it today and then ill put the antifreeze in it. than ill report back in

---AutoMerged DoublePost---

even though it had a brand new thermostat in there it must not have been working correctly. i pulled it out, put it back together minus a thermostat at all, and everything functioned normally, never hit a dime over 210*F. since all a thermostat is for is to help heat the engine up, now i have an electric fan itll heat up fast anyway since the fan isnt always on, im just going to leave the thermostat completely out one less thing to go wrong

Diesel Nut 02-16-2010 07:17 AM

actually the thermostat helps keep the motor cool as well. See, the thermostat stays closed during warm up, but also cycles open and closed in normal operation. The thermostat opens at the specified temperature, allowing water from the motor to enter the radiator, and cool water from the radiator to enter the motor. When the water has been exchanged, the cooler water causes the thermostat to close. Now, this allows the hot water in the radiator to sit there and get as cool as possible while the water in the motor absorbs heat until the water temp reaches opening temp and starts the proceedure all over again.

So, what I am saying is that yes, without the Thermostat your motor may never reach true operating temp, and when under a heavy load it may over heat. Put it back in. Maybe just try another one. They are like $10. You should have an opening temp of about 185-195.

tltruckparts 02-16-2010 06:34 PM

i took the new one back one back last night and they gave me another new one. ill put it in today and see what it does

---AutoMerged DoublePost---

ok, i put the new thermostat in and same problem!

if it take the thermostat out, and open up the top radiator hose, it flows water just fine, but it seems as when i put a thermostat in (4 different ones so far) it wont flow barely any water at all through the top hose.

what would be causing the thermostat not to open? i know the waterpump is good as it flows good when there is no thermostat and its brand new. but with a thermostat it never opens

ive done the proper bleed procedures, leave the cap off let it warm up to operating temp, then put the cap back on, and still the same problem.

if i squeeze the top hose with the cap on, it definitely has pressure so i know pressure is good everywhere.

someone please help me figure this out im at my whits end with this thing:argh:


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