Engine/Transmission (1994 - 1998) Over Heating Problem

[BLeary]

This last weekend we went over hwy410 near Mount Rainer, and the bloody truck overheated on us 2 times going east and once heading west . We were pulling our 3horse trailer with 3 horses in it and it started to overheat, and the trans temp light came on as well. The truck is a '94 3/4 ton 4x4 with 320k miles on it. Could the fan clutch be shot? or the radiator be plugged up internally or externaly? or do I have more troubles that I don't know about? This is the first time that I've ever had any problems and I'm kind of dumbfounded :{ . HELP PLEASE.

Thanks and have a good day

 

[RottenRon]

The truck will get warm pulling with a load, even with the fan clutch working properly, but it should not overheat. I had the same problem before going through the transmission. What is most likely happening is the torque converter is either slipping while locked up or not locking up. This creates massive heat in the transmission. The transmission fluid leaves the transmission, goes through an engine intercooler, then a transmission cooler, then back to the transmission. The heat from the transmission is actually heating the engine up, through the engine/transmission intercooler. I would say if you get your transmission rebuilt with some type of more efficient converter that will stay locked up and a valve body that provides added pressure to stay locked up, then your converter won't generate the heat, the transmission will be cooler, and therefore the engine will be cooler. That was the exact situation for me before a transmission rebuild. I recently towed my 5th wheel from Victoria BC to Anaheim CA (and return), along the coastal route with no heat issues, which certainly would not have been the case before.



Other possibilities people will chime in with: bugs/dirt blocking radiator, fan clutch issue, thermostat issue, air flow issue (upgrade air intake and/or exhaust). You should be able to hear your fan clutch kick in, it's definitely noticeable if you're listening for it.

 

[BLeary]

I had the Trans in 2nd with my foot init and pulling quite a grade at 35mph, the themostat works properly, but did hear the fan clutch kick in but was not very noticable, may it be slipping? I was also going to pull the radiator this weekend and blast it out externally. I thinking that it may also be plugged up externally. The reason that i dont think its the thermostat is because I've got the original type in it and I can watch the engine temp cycle from 190 down to 160 degrees.

 

[RottenRon]

My opinion is that the overheating is due to the transmission. When in second, or anytime the converter is not locked up, it is generating a whole pile of heat which also heats the engine coolant. I had the exact same problem when towing heavy up steep hills. In my opinion a transmission rebuild with a better converter and valve body is your solution. A more efficient converter will not generate as much heat when not locked up. A better valve body will allow you to lock up in all forward gears. When I tow up something really steep now, I drop down to second, lock up the torque converter, and cruise up the hill with no heat issues whatsoever.



I think your overheating issue has absolutely nothing to do with your thermostat, radiator or fan clutch.



Just my opinion.



Ron

 

[AndyJohnson]

I agree probably the transmission especially with that kind of miles and the dodge auto isn't exactly the most reliable. Although if your pulling the radiator you might as well take it to a shop and have it rodded out.