Installed new cummins thermostat...
#1
Installed new cummins thermostat...
I just put in a new thermostat from cummins (part # 3928499), and I'm getting huge temperature fluctuations. I read that this was a problem for unloaded trucks because of the large radiator, but I thought the new thermostats from cummins would fix the problem?
When the truck is warmed up and I'm cruising down the hi-way the gauge jumps from the halfway mark down to under a quarter and then climbs back up and repeats. I drive most of the time unloaded or very lightly loaded so I would like to fix this problem if possible
When the truck is warmed up and I'm cruising down the hi-way the gauge jumps from the halfway mark down to under a quarter and then climbs back up and repeats. I drive most of the time unloaded or very lightly loaded so I would like to fix this problem if possible
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captain_stabbin (10-05-2010)
#3
#4
Drain about one gallon from the radiator. Remove the upper hose and neck together, then pull the t-stat out. Pour coolant into the block where the t-stat sits until the block is full. Tighten the neck back down, then fill the radiator, squeezing the upper hose until you purge all the air, and the radiator is completely full of coolant. Also, be sure the recovery tank is at or just above the max mark. Drive the truck and see if the problem still persists. If it does, need to get a new t-stat.
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#8
I read that it was normal, but I also read that it had been fixed by an updated thermostat. I guess I just don't like the thought of the engine being heated and cooled so drastically all the time. But I do like having a real gauge
Quote from geno's garage:
So according to this cummins sold me the "old" thermostat, I guess it's my fault for not asking for the new part number specifically, I assumed they didn't sell the old one anymore . Has anyone tried the "new" thermostat, how does it work? I would think it just opens slower?
Quote from geno's garage:
# Wide fluctuations of the temperature gauge
* the result of a large radiator, it is relatively harmless and normal
* Cummins has released a revised T-stat that does fix the "problem". The revised T-stat Cummins part number is 3934373. (The old T-stat Cummins Part number is 3928499. )
* the result of a large radiator, it is relatively harmless and normal
* Cummins has released a revised T-stat that does fix the "problem". The revised T-stat Cummins part number is 3934373. (The old T-stat Cummins Part number is 3928499. )
#9