background-had a bad coolant leak in my 94 Bronco's 5.8. Turned out to be three intake manifold bolts corroded from the inside out and broken off in the heads. Engine pulled and rebuilt. .020 over, completely balanced, msd distributor, bassani headers/y-pipe, flowkooler water pump, electric fans installed, timing advanced to 12 degrees.
The engine would idle all day long but would overheat as soon as it was given gas. No problem up to around 35 mph either, after that it was pegged. Replaced hoses, 165/180/195 degreee thermostats, flushed radiator and heater core. Running with no thermostat solved the problem instantly, but I didn't feel comfortable with doing that since it ran too cold. Finally figured out that the flowkooler pump was overpowering the system with vacuum. The hoses were being sucked shut once I got it over 1000 rpm or so. I replaced the bottom with a gates vulco whatever super universal hose and that one worked fine. Now the upper hose closes off. Couldn't make a universal work there and a stainless hose was about $70. For $50 I replaced the flowkooler with a new, stock-style pump from napa. Problem solved, no overheating.
Now my problem seems to be reversed. I can't get the engine to warm up past the 'C' on the gauge. My motor never ran hot but this can't be good for it. The heater will blow hot air, but I should at least be reaching the word 'normal' on the gauge shouldn't I?
Any ideas?
Mike

 

you need to have a 195* tstat in there. and hook up a mechanical temp gauge. the stock ford gauges suck.

 

I have a 195 stewart warner thermostat in it now. It just acts the same way it did with no thermostat. I can almost reach the 'N' in normal if I sit in the parking lot and rev it up for 10-15 minutes. I might try the mechanical gauge bit though.
thanks

 

Perhaps the Tstat stuck open?