ok here it is. been struggling with this for about two weeks now and am fed up and out of money. a few weeks ago we had a cold snap and it seems i was a little low on antifreeze and it all froze. pulled the belt and drove it up the block to my friends shop and thawed the truck out. filled and ran and had no leaks except a hose and the seal around the block heater. fixxed and ran but truck runns a little hotter than normal. used to run 1/6 the way up the gauge. now runs at 1/3 but goes back and forth from 1/3 to 1/2 and back while driving on the highway. replace water pump and thermostat. (real cummins stat) and am going crazy as i am back logged and need my truck now. some one said head gasket but i have no leaks no watter in the oil and no bubbles in the radiator. so only things left are radiator (may be clogged???) or temp sensor???. i dont know. i neeed my truck back on the road. now. is the temp this high on the gauge normal. can someone explain what temp valuse the lines on the gauge mean??? i need help

 

I wouldn't worry about it if it's holding water jacket pressure, not leaking and everything looks good like you said. Keep checking the fluids / radiator and top up as needed. Maybe just some air trapped in there causing your symptoms.

 

dont think its air. have drivven it for a while drained and refilled and after lots of air bubles always levels out at the 1/3 mark and goes back and forth from 1/3 to 1/2. and this is running empty. i have a 5000 lb load i pull with this and cant afford an overheat. hottest it ever got before with the trailer was just under half and that was fully loaded up a long steep grade.

 

Could be freezing in the radiator loosened up some chunks in there. Next time you park it hot feel all around the radiator to see if it seems to be evenly heated across the entire surface.

 

On my 98 12valve, when your driving down the highway you can see the guage move when the thermostat open and closes. It's not uncommon to see this happen on a cummins. And on the real cold days here you can see it go up and down all the time. Big rad, big engine, cools down very fast.

If it's just your temp guage, I would not be worried.

Corb

 

The problem seems to be that this behavior changed after some episode, which makes it by definition, "abnormal."

 

i have bought 2 01 cummins and first load i pulled with one it over heated and the othere did it just driving through the mnts empty but both were because of the radiator. tried flushing them but nothing worked till i replaced them now they run perfect

 

thats were i am going next. first coolant flush after the freeze looked like crap. well it a shot. what do you guys think

 

If you pull the radiator, stand it on its side and flush it out from the side that feeds the motor/the bottom hose/ just make sure the bottom hose port is at top then flush. This way anything that got plugged will try to go the same way it entered the core, sometimes this works real well, once I get all I can I change the direction of flow a couple times. If you can hook a hose up to hot water it helps too.