I just picked up a 1986 Ford F250 to use as a tow rig. It runs very well but the temp gauge sits at 3/4 when running down the freeway? It sits at about 1/2 when driving in town. I replaced the radiator becouse it was leaking and I replaced the thermostat but it still runs at 3/4. Any ideas?

big,small or six? my 460 was doin the same,190 around town and 210 on the freeway, i had to change the water pump and put a flowcooler plate on it to help from cavitating. new radiator, 180 t-stat, new clutch and 6 blade fan. now it never goes over 180 and it used to run at 210 all the time. also check the sender. good luck!

get a guage

Get a gauge with numbers on it. You'll probably find that 3/4 is like 210* which is fine and normal. With stock temp gauges I always figure that it's not over heating until the needle is completely into the H. Hell, I've towed over 9hrs once with my temp gauge at 7/8ths and 15/16ths bordering on 31/32nds. Never hit the "H" so it wasn't overheating, it was just really hot:D

Get a gauge with numbers on it. You'll probably find that 3/4 is like 210* which is fine and normal. With stock temp gauges I always figure that it's not over heating until the needle is completely into the H. Hell, I've towed over 9hrs once with my temp gauge at 7/8ths and 15/16ths bordering on 31/32nds. Never hit the "H" so it wasn't overheating, it was just really hot:D

It can even be at 63/64ths. But that isn't hot yet. "As long as it isn't touching the H".:flipoff2:

It can even be at 63/64ths. But that isn't hot yet. "As long as it isn't touching the H".:flipoff2:

Bad tech. Once you get to where yr splitting hairs finer than 32nds, you have to switch to the other unit of measure..BCH, RCH..etc.:flipoff2: Mine runs just an RCH below the peg when I'm towing.:smokin:

try a better fan blade or replace the clutch on the factory fan

get a guage

Or more specifically,

Get a gauge with numbers on it.

To be precise, a high quality gauge. I like Autometer. It doesn't make sense to play around with anything else at this point untill you know exactly what your temp is. I've seen shitloads of "problems" that really weren't....except as reported by shitty gauges.

yeah a $40 gauge would have told you if that stuff really needed replacing or if the stock ford gauge and sender was a piece of shit. Wait, send me $40 and I'll tell you the stock ford gauge is a POS :flipoff2:

Thanks to everyone who responded. Sounds like I need to get a gauge.

You need to learn how your gauge is. The gauge on my old f150 always set a 1/8" to the left of Low. My F250 always set a 1/4" to the left of low..

or spend $30 bux on a gauge that has number like my other f150.

Anyone have a 6 blade fan they want to sell?

Sure its not the block or head warped?

if it only runs hot at highway speeds then the fan is not the problem...at highway speeds (55+) the wind forcing itself in exceeds what any fan can pull in......have you bought a guage yet?? like said before, stock guages have been known to lie occasionally....210* is normal running temp for any motor, when you go with lower thermostats you can get the motor down to 180 or so like supervert said, but all your really doing is making your heater blow a little cooler...my 460 ran hot on the highway for about 4 years before i figured out what was causing it, and when i say hot i mean hot...my motor would fluxuate between 230* all the way up to 280* maxing out my sunpro guage (but not boiling over at all) i didnt believe it so i hooked up a second brand new guage to a different water port, and it read exactly the same as the first one i installed....all this after i already installed a brand new radiator, water pump, Tstat and all new hoses (the new hoses are the only reason the high temps didnt leave me stranded)....i finally got fed up and tore my engine down to the shortblock, thats when i discovered the whole back half of my motor's water jackets were clogged off....the front half of the water ports had clean green antifreeze, while the back half looked like brown lake water after a storm....i guess too much radiator sealer was used over time and the ports clogged shut....lacking money for a good acid dip and machine work, i cleaned the ports out the best i could with various tools and some heavy wire....now my truck dont run hot anymore, and it still has all the same parts as before, and BOTH of my temp guages stay right on 210* whether im haulng a load or not....anyways, make sure all the cheap parts are in good shape (Tstat, radiator hoses not collapsing, radiator cap holding good pressure) before tearing anything apart.......this is a long shot, but i have seen it happen, sometimes the valve in the heater hose needs to be removed cause it blocks the flow through the heater core, and coolant systems sometimes need to have that open for a "bypass" past the Tstat.....is usually needed when a system has a flow problem....good luck...