95 3.9. engine has been running hotter and hotter lately, now it seems the gauge is all the way to the top (Hot). coolant level is full and appears clean. no thermostat ( i thought that was the problem and yanked it in an emergency late night fix) coolant flows fine. although it seems to want to expand right a way and start to overflow. i doesnt seem to be any air in the system and certainly does not run out. no water in oil. i replaced the sending unit as i thought it was going bad. when the temp gauge goes all the way up i stop and hear the loud ticking sound associated with a hot engine but no boiling or over flowing in to side tank. did replace radiator cap as well. the radiator tank reads 226 on the laser temp when hot. i flushed the radiator in december when i replaced the water pump. and i see good flow when the cap is open. cant figure out what is causing this problem or what i should test next. i tried towing a trailer and that was not a good idea. that got the radiator boiling ( i smelled it and stopped).

 

Measure the temp of bottom tank too and see if it is significantly lower than the top tank. Some say that removing the t stat does not allow the coolant to stay in the radiator long enough for it to reduce it's temperature.

Is the fan spinning with the motor?

 

fan is spinning. bottom hose seems to be in the 165 range going back to the motor. heats up real fast when i drive over 45 mph. (of course we are in the record temp days right now in florida) just started hearing the ticking sound today. (loud)

 

Once the engine is fully warmed up, shut the engine off and run your hand down the radiator to see if it gets cool at any point. If it does you have a plugged radiator.

 

cant really tell a difference in the feel of it. tank on top is H A H. engine seems to have consumed or burned up some oil. that just started! also right after i started it today with the cap off after a minute or less a cloud passed by the opening and bubbled. then it went back to the green coolant flowing by. the coolant does look a little cloudy not the neon green that is was but it seems fine after that initial burst of whatever it is.

 

i rented a pressure tester from auto store, pumped to 15 and waited. dropped to 10 within 2 minutes then seemed to hold near there. no leaks anywhere. oil is clean, compression is good. inspected all around the block and found no coolant. removed tester and coolant had dropped about 2" in radiator. no idea where it went. cant find it anywhere. added more coolant. started it up, same initial cloudy foamy burst then steady green coolant flowing by. even with all the overheating the coolant level has remained the same. and i added the oil back in and so far it seems to be holding steady and it remains spotless. i did replace the temp sending unit so i know that should be working and not giving me a false reading. temp seems to be 50 degree difference top radiator hose to bottom when it is running hot. i am just at a loss here.

 

I have no idea if this is even a possibilty, but if an LA engine waterpump were installed on a Magnum engine, the impeller blades would be ineffective, because with a serpentine belt, the water pump spins opposite direction as an earlier LA V belt engine.

I have a newish aluminum radiator, but my IR/lazer thermometer does not take an accurate measurement on shiny aluminum so I cannot tell you the temp difference in top and bottom tanks on mine.

Hope you can get a real answer and post back the fix/result.

 

Stick a piece of black electrical tape where you want to take the reading, wait a minute or two for the tape to heat up, finally take the temperature reading while focusing on the black tape.

 

Too much effort, and I'd hate to have electrical tape adhesive corrupting my shiny newish radiator. HAHA

Any Idea if a LA waterpump would even fit on an Magnum engine?

 

i dont have the shiny problem, but that is one of the reasons i shoot the black hoses right off the radiator. i dont see the water pump being the issue. its been there for a year and i get serious flow across the neck. i actually stopped at a mechanic late this afternoon, he was in a hurry but thinks its a combination of thermostat being out, and radiator that is old and worn out temp gauge. his theory is 3 small things add up to major problem. i found a new radiator here local for 135 and i have a new therm so i get to spend my 44th sweltering in the florida sun hoping this fixes things. i just want to know why i am losing pressure and NOT losing coolant? i have been told over and over this is okay but down one side of my block i have 150 psi 145 psi 135 psi. and down the other side i have 150 psi all three cylinders. supposed to be okay because it is less than 10% change but man i dont know. i did read in another van thread about a guy towing and overheating and he had a bad radiator and all so hopefully this fixes mine. we shall see.