my truck has the 53 block in it and i just bought it over the weekend, the truck wont come off the 140 line, doesnt matter how long i drive it and im getting no heat in the cab and the air is always cold, im guessing i got a bad thermostat in it and was wondering which thermostat i should go with from cummins, the 180 or 190 degree thermostat? or should i leave it as is so i dont have the pressure build up and have it crack the block?

 

190 and possible plugged heater core... Find the hoses in and out of the core on the firewall. Dissconnect them and run a hose both ways through it and see what comes out. Another cause is low on coolant...

 

might not even have one in it. if it had one and was stuck open it would still try to warm up. some. if i put a new one in it i would just go 180 its whats in mine works fine. less heat in the winter but also less heat in the summer.

 

The heater core is not adjustable in coolant flow, but there is a blend air door. It controls how much air goes through the heater core or bypass it.
These trucks, with a 190 thermostat< will rarely overheat. They cool very, very well. Montana, 93* day, externally plugged radiator, and putting across parking lots was the only time I've seen my truck exceed 210*.

 

i think what was ment was something, rust or scale build up clogging up the coolant passages in the core its self. you must be more willing to let your truck get hot than me, 190-195 is as high as i ever wanna see mine go to. with my 180 t stat pulling a 38 ft trailer i get to 185ish. ive seen mine go to 205 1 time and it was well over 100 outside.

 

Mine still has the stock thermostat and I cant remember the last time i pressure washed the radiator, it was definitely before I got rid of the breather can. The highest mine ever gets in the summer is 205 or 210, on a 96 degree day.

They definitely have an effective cooling system to say the least

 

so what t-stat to get? the 180 or 190, i dunno if the guy has it the way it is because of the 53 block in it or what, could really use some direction here on what i should do, id hate to crack the block but it would be nice to run around in a warm truck, like i said after i go out and run it and come back and put my hand on the valve cover its still kinda cool, and still have no heat in the truck!

 

I really don't think a thermostat opening temperature difference will determine the longevity of your block. Pressure will be built up regardless, and the radiator cap will determine how much pressure the system will hold. Personally, I would go with a 190 Thermostat. The heaters in these trucks need all the help they can get warming up the cabs. The truck will still run normally in the summer, but might be a little nicer to drive in the winter.

 

190 like I mentioned b4...

 

most places only stock the 190 and they work fine. no stat kills efficiency of the motor they need heat still to run proper.