I have a '93 dakota 5.9l 4x4. I recently replaced the radiator, hoses, thermostat and cap. I am filled with 50/50 fresh coolant. I have pressure tested and no pressure loss. (I pumped up to 20lbs and it held for ten min. I also tested the new cap, and that tested fine. If I get the engine hot, not from normal driving, but when tranni gets hot, after stopping it bubbles over profusely into the overflow bottle. the needle never gets out of the normal range, just to the upper end. The aux fan works, fan clutch has no play no wobble/leak/noise from water pump. No white smoke, no oily radiator fluid. Any ideas?

 

Looks like you did a swap with that 5.9. Me too! What was in it before the swap? If it is the V6 radiator that might be the problem. I will move this to the 1st Generation Dakota Sub-Forum.

 

could be like crazy said could be the wrong radiator. if your gauge is stopping at the halfway mark it probably siezed(mine was doing this for a while). you shouldn't run your truck super hot for a long time, i lost mine after running my truck on the line before "h" for just over 10min trying to get home and i had to swap another one in(but i went with a manual this time).