Sub won't run over 155 degrees...

[blazerbones]

Ever since I flushed the coolant and put in an aluminum radiator, my 90 sub with a 350 won't run over 155 degrees. I thought it must have had the 160 degree thermostat in it from PO. 180 degree thermostat brand new just changed... runs at 155 before and after new thermostat. bad sending unit? Any ideas?

 

[4xcrazy]

try the 195 t-stat, like it's supposed to have anyways

running a 180 t-stat in the winter time especially will keep your computer in "cold mode" uses more fuel...

had this little issue with a Camaro i owned with a lower t-stat, and cooling fan temp switch, ran too cool to keep the computer "happy"

 

[pauly383]

Well Aluminum , from what I gather is way better for cooling than the stocker .

 

[imiceman44]

Ever since I flushed the coolant and put in an aluminum radiator, my 90 sub with a 350 won't run over 155 degrees. I thought it must have had the 160 degree thermostat in it from PO. 180 degree thermostat brand new just changed... runs at 155 before and after new thermostat. bad sending unit? Any ideas?

How do you know it runs at 155, the guage?
It's not that accurate.
If you check it with a good guage and it still shows 155 then you have a bad thermostat that is stuck open.
You should always have at least what the thermostat is or 5 degrees more.
with the 180 you should be between 180 and 185 if it functions properly, even if you have great cooling.

 

[blazerbones]

thanks for the info guys. I think the gage is off, 'cause I've changed the thermostat twice now. I'll check with a good gage to confirm and change to the 195 tstat .