Hey, my radiator and water pump recently went out so I had them both replaced. Before my radiator and water pump went out, my temp gauge would read between the 'o' and the 'm' on 'normal' in pretty much all driving conditions. After I got the radiator and water pump replaced (about a month ago), everything seemed to be fine until a few days ago. A little bit after accelerating (on the highway), my gauge will go up to the 'l' or almost up to the red bar, and then slowly go back down to the 'o'. It never used to get this hot before, and I don't really gas it while accelerating so I don't see why it could get so hot. Also, after I get off the highway and drive through town, my gauge goes back up to the 'a' or 'l' and stays pretty high while I'm driving in the city. I know that it should run hotter in city driving conditions, but it never used to run this hot before and it's such a big jump in temperature from the highway.
I've left my bronco in neutral after driving and waited for it to cool down a little bit (with the engine still on) and then put my foot on the gas to 4000rpm to see if it would heat up. It seems like no matter how much i rev the engine (I don't leave it too high because I don't want to ruin my engine), it doesn't get any hotter than the 'm' while I'm parked. I've also tried this after i've had my bronco turned off for a while, and it doesn't get that hot.
It runs hotter much than it used to while I drive in the city, and it seems to run the hottest when I drive in the city after driving on the highway.

I don't know if maybe my thermostat is bad or if it could be the fan, or maybe my temperature gauge is bad... If anyone knows why this might be then please tell me.

Thanks

Oh, and I have a 1996 bronco, 5.0, manual transmission

 

best to change it all...but that really is not that hot...
i would change it all like thermo and sending unit.
and did you flush the sytem out?

 

pop the cap (be careful) and hold the throttle open to about 2k rpms for a couple min. and burp the system of any air. you'll see it bubble up out the cap and spew some antifreeze. once you think you got all the air out, top off the coolant and replace the cap.

you might have air trapped in the system

 

And get you a real gauge. An autometer one or something. The stock gauges are bogus.

Bob

 

I just did the water pump in mine and a couple things come to mind that you might check.

You might check that the fan clutch is working. With the engine off (duh - but I never know) spin the blades with your hand. They should spin but with some drag - not stiff and not free wheeling. I can't remember if it's possible to put the blade/clutch assembly on backwards, but you might check for that as well - pushing rather than pulling the air.

When you put the fan shroud back on did it seat flush to the radiator? It could be that the fan isn't pulling air either because the shoud is not up against the radiator or the face of the radiator is covered somehow.

Make sure that your coolant is in the right range of mixture. I'm near Chicago, so I tend to keep mine on the richer side - about 75% antifreeze. Anything between 50% and 75% would be good.

Could it be that your dying radiator filled the new one with gung? The only way I can think to test for flow there is to open the radiator drain and run a garden hose full blast to see if the water is crossing the rad like it should. I know I ran the garden hose through the heater hose with the bottom radiator hose off before I closed it up to try and flush out the core & block.

Nice nick, btw. How's your sister? >:-)

Calvin