ok my truck runs very cool for awhile(weeks or months) then out of nowhere it'll start overheating all i have to do to fix the problem is drain the radiator and refill it, it'll run cool for awhile then start overheating again, every time i drain the water it is brown with rust in it, i'm thinking the rad just needs rodding but i'm not sure. what do yall think? thanks in advance, Justin

 

What kind of situation are you in when it overheats? Traffic or normal driving? Could be the coolant thermostat. The rust in the water is probably just what has rusted is being cleaned out. Did you flush it really good? Make sure you get all of the brown color particles out you don't want it to be running around your engine block.


By the way, LOVE Metallica.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

any kind of driving it overheats and i flush it the best i can but there always seems to be more rust and what not when it starts to overheat again, thought it was the fan clutch one time and i flushed it before i put the clutch on, well that fixed it so i took the clutch back. i'm thinking if i had the rad. rodded and then installed a 160 thermostat and put on electric fans(just somethin i want) then it shouldn't have any trouble staying cool.

 

I've been told to use a 180 degree thermostat for an electric fan. I think i heard 160 is low, but I could be wrong you might want to check on that unless you are 100% positive.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

Sounds like your thermostat is sticking. Replace it with at least a 180° thermostat. That is really on the cool side if you have a '88 or later truck. If you go down to 160° the injectors will stay in rich/start mode because the computer thinks the engine has not come up to temperature yet. The rust is due to refilling the system with plain water. If you use a mix of coolent and water that will inhibit the rust for at least a year. Remember to have the heater on full hot when you do the flush so that area will be clean too.

 

I kind of lean to clogged up radiator with the clogs moving about due to loose rust. You probably need a good forward and reverse flush and a chemical flush, followed by another forward and reverse flush.

After a checmical treatment, it has been my experience that the T'Stat will fail within a couple thousand, so after the flush would be a good time to use a new one.

Good Luck,

Jim Henderson

 

ok how do i know where 160 or 180 is on ym temp gauge? i flushed the rad lastnight and now it dosen't get above the O in the word normal, last night before i flushed it it was hot enough to make the red "engine" light come on. perhaps my t'stat is sticknig open for awhile then slowly shuting and sticking, flushing the system takes presure off of it and it opens again? i'll just go ahead and change the t'stat it's a cheap part anyways. also if it is sticking open and the truck is overcooling(like it is now) an early post said that with a 160 t'stat the computer thinks the truck isn't warmed up adn will run rich all the time, i think this might have something to do with my bad fuel milage. i'll get a new t'stat in the truck prolly saturday afternoon and we'll see what it does, also where should the temp gauge read?

 

You can't tell where 160-180 would be, thats the thermostat temp at which it opens, not the temp where the sensor is. Make sure the temp gauge doesn't go past the L in normal, if it does shut it down and let it cool off. You don't want to spend time past the L in normal. The only way to tell what the temp is would be to install a real gauge for it.


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

BTW, you can test a T'Stat by putting it in a pot of water with a thermometer. Heat the water and watch the thermometer and the T'Stat. You should be able to see the T'Stat pop open. when it does, read the thermometer. That is the temp the T'Stat opens at. Note that I suspect the T'Stat rating is probably not exact, I would guess there is 5 degrees or so of tolerance.

The temp gauge in our trucks is not exact and unless you went thru the trouble of measuring temperature with a thermometer and cross referencing against the gauge, you just have to take the reading as relative.

In my opninion the gauge is good for the following ranges... Cold, warm, normal operating temperature, a little too hot, hot, way hot and dangerously hot. On my 94 F250 460 it usually runs between the N and O on the gauge, even when towing a trailer. Towing on hot days on flat ground it may ride aroung the R. On 100+ days with trailer and up hill, I have not seen the gauge go past about the A.

Good Luck,

Jim Henderson

 

ok my truck is running between the N and O and it's been about 87 outside. so i guess it's doin ok and not over cooling like i thought(there goes my gas milage theroy) but i'm still going to just drop another t'stat in. thanks for all yalls help.

 

Much better responses now huh


Primary rig is Green Thunder:
95' F-150 XLT 4x4, 302, 5 spd, MSD 6A, Flowmaster Exhaust, Sunroof, Clear corners w/ Diamond headlights, CD player with 2 10" subs and some 32" BFG Muds .

Thats it for now, saving for a stang. Check out my Gallery for a look-see.


Justin - One Happy FTE Member

 

My truck also only sporadically touches the 'R' in normal. I think that's exactly the right temperature. I'd say do a chemical flush. Then fill the system up with regular tap water. Run to operating temperature (TS opens) with open radiator cap (careful!). Open drain plug and replace any drained water with a garden hose in the radiator. Run the water through the system until the draining water is completely clear. Drain system. Fill with *destilled* water and antifreeze (only 30% antifreeze will suffice) and drive for a few days. You'll probably notice that the coolant is murky again. Drain and refill with destilled water until the coolant stays clear. That's what mine's due for pretty soon.

 

A common missconception is that a lower numerical # on the thermosate makes the engine run cooler. This is not true. since the thermostate opens and closes throughout driving a hotter thermostate will actually let the engine run cooler as it allows the coolant more cooling time in the rad.