coolant temp

my 96 5.7 seems to run a bit cool ,according to the scan gauge it runs around 170 to 173 on a 50f day and the dash gauge seems to agree (for what its worth with only a number at the start and end) . Temp sensor out of whack or is it really running that cool? it comes up to that temp normally so it seems that the thermostat is working.
whats the procedure to check it

my 96 5.7 seems to run a bit cool ,according to the scan gauge it runs around 170 to 173 on a 50f day and the dash gauge seems to agree (for what its worth with only a number at the start and end) . Temp sensor out of whack or is it really running that cool? it comes up to that temp normally so it seems that the thermostat is working.
whats the procedure to check it

Not exactly sure what your concerned about. Seems like your truck is running fine. Typical gauge runs max 260 degrees, you're in the median range. If while operating the vehicle the gauge is fluctuating, then I would think you should be concerned.

my 96 5.7 seems to run a bit cool ,according to the scan gauge it runs around 170 to 173 on a 50f day and the dash gauge seems to agree (for what its worth with only a number at the start and end) . Temp sensor out of whack or is it really running that cool? it comes up to that temp normally so it seems that the thermostat is working.
whats the procedure to check itThe thermostat is the most likely culprit. These cooling systems are very efficient and if the thermostat is stuck open a little, the engine will warm up, but not reach operating temperature. It is much more common than the sensor malfunctioning. Based on the price ($5-$7) and the ease of the repair, it is generally advisable to just replace the thermostat if you suspect they are bad.

Not exactly sure what your concerned about. Seems like your truck is running fine. Typical gauge runs max 260 degrees, you're in the median range. If while operating the vehicle the gauge is fluctuating, then I would think you should be concerned.The normal operating temperature is 195. Running below that causes the engine to run less efficiently. The OP's temperature is also very close to the temp at which the engine enters closed loop. Any cooler and it may stay in open loop, which would cause more fuel consumption.

Another concern is that running any engine below 180 degrees doesn't allow the oil to get warm enough to boil out condensation. This along with the less efficient operation can more than double normal engine wear.

my 96 5.7 seems to run a bit cool ,according to the scan gauge it runs around 170 to 173 on a 50f day and the dash gauge seems to agree (for what its worth with only a number at the start and end) . Temp sensor out of whack or is it really running that cool? it comes up to that temp normally so it seems that the thermostat is working.
whats the procedure to check it

you should be running at 195deg F range. not 170 deg F ...



thermostats made today are not very good...

get a pot of water and heat to 212deg F boiling . using a temp gauge measure temp of water at 212 , themostat should fully open ..stop heating the pot. as the temp drops measure at what temp the themosat closes..

repeat with new thermostat.. I do this when installing new thermostats.. before install...

could be you have a 180 deg f stat in there now !

it used to rum warmer with the dash gauge pointing to 12 oclock now its more like 1030 thats why i checked it with the scan gauge. Scan gauge says it is going to close loop. I'
ll pop a new stat in and try that,thanks to all.