I recently bought a 1984 Bronco II, v6, 2.8L, 4spd 4x4, 90,000 miles. It runs hot and I can't figure out why. It has the vertical temp gauge that spells NORM and the needle sits at top alot. It moves between the middle (between O and R) to the top of the N. The odd thing is that it seems to run hotter in the morning when it's 40 degrees out versus the day time in the 60's. Also it will cool off a little when going up hill. It doesn't make any sense to me. I have replaced the radiator cap and thermostat. I flushed out the radiator, ran some cleaner through it and straightened out any smushed fins. Any ideas?

 

I had the same problem with my 88 with a 2.9...one day when it got close to overheating, i realized the radiator was leaking where the plastic is "soniclly welded" to the metal part with the fins. Also, the upper hose was swollen. I replaced the thermostat with a low-temp thermostat, replaced the water pump. I removed the fan and fan clutch and added a aluminum fan and 3" spacer without a clutch. As for the radiator, mine was a thin 1-row rad. I bought a 2-row aluminum radiator that is twice as thick as the stock one. It also has twice the amount of fins per inch as stock-that helps with the cooling.

 

I never did figure out what the problem was, i think the radiator was clogged. When i removed the water pump, there looked to be calcium and mineral build up in the engine block, from someone using tap water instead of antifreeze or distilled water. Also, i installed exhaust wrap on my headers, it keeps most of the heat in the exhaust instead of under the hood

 

I had a similar issue with my Bronco ll. It might be alittle air bound, an old mechanic gave me a tip after I installed a new water pump. He told me to install a flush tee on my heater core hose and fill the system that way. Apparently your are filling on both sides of the thermostat.

 

Those guages are notoriously inaccurate, I have seen them fluctuate all across the board and then settle back down to a normal reading.
Install a real mechanical temp gauge before you tear into it, it may not be overheating at all.

 

right, i have a sunpro guage, it just has a thingy that screws into the drain plug thing on the bottom of the radiator

 

What gauges are out there that work and are cheap?

 

Sunpro is one of the cheaper brands out there that works well.
If you are feeling rich, theres alway Stewart Warner, VDO and Sun.