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Soon to be bagged!!
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Discussion Starter · #1 ·
ok so its an 85 S15 with a carb'd 2.8 V6, automatic tranny 2WD. it will run just fine if i do not go more than 45mph or so. but i take the freeway home everynight and i am going about 70-75mph then, and thats when it starts to get hot it'll stay at about 220 degrees until i get off then on the rest of the way home it will skyrocket until i get home, after crusing at about 40mph for 5 miles or so. also when i am in stop and go traffic in town it does the same thing. coolant is good, there is no thermostat, they guy i got the truck from took it out cause he was having the same problem and it got better after remocing it.

i was thinking the fan clutch is wiggin out, and napa said there is no replacement for it, just an aftermarket electric fan. any ideas?
 

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I would make sure that the cooling system isn't plugged up. Use the correct amount of
coolant,put in a good thermostat. Also make sure the cap is working right. Go to a wrecking
yard for a clutch fan. Let us know what you come up with.:)
Billy the Kid AGF
 

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Awww..you ain't got shit!
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I wouldn't suspect the fan if the truck is getting hot going down the interstate. You could take the fan completely off the truck as long as you are moving fast enough to make air pass through the radiator to cool the motor. Napa is full of sh*t about the clutch. You can get one anywhere...except Napa apparently...Definately suspect the thermostat. Cheap and easy to replace. Whoops...you don't have one..sorry...I would pull the radiator and just go ahead and have it serviced. Really then the only thing is the water pump. It's unlikely that it is bad unless it is leaking or the bearings are worn out. However, you should not rule it out as I have pulled them off before and seen several fins broken off of the impeller. Hope that helps..James
 

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Soon to be bagged!!
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Discussion Starter · #4 ·
thanks, im just gonna get a new radiator, a taurus electric fan, new stat, new cap and water pump, ontop of a couple of flushes
 

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InfiniteS10 said:
thanks, im just gonna get a new radiator, a taurus electric fan, new stat, new cap and water pump, ontop of a couple of flushes
Wait before you start spending too much money - when was the last time that you or previous owner replaced the radiator hoses?

The hoses can break down and get soft. In turn at higher rpm the water pump can actually draw enough suction that it will collapse the hose on the intake side of the pump and cause you to run hot.

Check your hoses before you drop too much money.

Jeff
 

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Pushrod for life!
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also check the sending unit and guage to make sure that they are not at fault
 

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Soon to be bagged!!
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Discussion Starter · #7 ·
i can tell it is running hot for sure because when i turn it off the radiator is overflowing into the overflow tank.

the hoses were just replaced about a week ago.
 

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InfiniteS10 said:
i can tell it is running hot for sure because when i turn it off the radiator is overflowing into the overflow tank. the hoses were just replaced about a week ago.
Two possible cause, one being the radiator and the other being the water pump. Radiator could be clog internally and the water pump impellar could have seperated from the shaft.
 

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Soon to be bagged!!
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Discussion Starter · #9 ·
i am going to do the wp first, then the rad if it doesnt solve it
 

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My radiator shop will rebuild (clean, paint and rod out) for about $50 which is real cheap compared to a brand new one. YOu can usually do this two or three times through the life of the radiator. Having mine done now as preventative. Been watching the needle climb up higher than I like lately.
 

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before you get too drastic on this check to see if you are getting any flow through your hoses. Start up your truck and wait for the engine to get to normal operating temp. After this is done grab a hold of your radiator hose and squeeze it. You should be able to feel the water surge through if it is good. If you feel this surge then your water pump is good and there is no major clog.
 
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