Temp getting HOT!

[FordLover]

after a romp thru some mud, I had the battery light come on. After washing out the alternator, I could get the light to go off while reving the motor.
So I replaced the alternator, problem solved.

But now the temp is getting hot, well past 1/2 way on the guage, like I've never seen it before. After replacing the thermostat, and flushing the hell out of the coolant system (there was a ton of sand/grit in the system) I could barely open the old thermostat with my fingertips. I changed the radiator cap along with the thermostat (192 degree with jiggle valve) installed correctly, and it's still getting way too hot. (around the L on NORMAL)
BTW, it's been about 50 degrees F around here if that helps any.

So what am I missing? The fan clutch is working great, no leaks.
and the temp rises if your idling or doing 70MPH down the freeway
-Martin

 

[mhn3773]

does r cooling system have an air bubble in it? thats the only thing i could think of that would vary with speed or outside air temp

 

[RFR2212]

You sure the radiator itself isn't packed with mud? If the fins are packed with mud, it's not going to cool well at all.

 

[jasonb]

i've had that happen as pete said above. they didn't even look really packed but it was enough to cause it get too hot at long stoplights!

 

[X~FACTOR]

Water pump might be all clogged up also. Water pump usually last the life of the truck but from what you described with the mud and grit and all its worth considering looking at.

 

[FordLover]

Fixed it!

Turns out it was packed up really bad with mud. Took about 20 minutes of constant water spray to clean it up. I guess I learned why not to fly thru mud holes so fast. Thanks for all the suggestions guys!
-Martin