5.7/350 thermostat question

[Deserthigh]

Ref: 1986 GMC3/4ton 4x4..California Stock

 

Just dropped in a new radiator and thermostat. Stayed with the 195 thermostat. Before the swap out it ran at 210 all the time after warm up. today it ran at 160-180.. should it not go on up to at least 195? Pretty sure the thermo is in with the spring down...exact same radiator as the old one...but the old one may have been clogged...

 

so..does the 195 usually register 195 on the gauge or was 210 degrees what the 195 should result in? Wfhy would it be running so cool now? finally, is 160 -180 to cool for a 1986 choked nearly to death with emission controls?

[90GMCZ71]

Ref: 1986 GMC3/4ton 4x4..California Stock

 

Just dropped in a new radiator and thermostat. Stayed with the 195 thermostat. Before the swap out it ran at 210 all the time after warm up. today it ran at 160-180.. should it not go on up to at least 195? Pretty sure the thermo is in with the spring down...exact same radiator as the old one...but the old one may have been clogged...

 

so..does the 195 usually register 195 on the gauge or was 210 degrees what the 195 should result in? Wfhy would it be running so cool now? finally, is 160 -180 to cool for a 1986 choked nearly to death with emission controls?

 

Same thing recently happened to me. 1990 GMC 5.7. Plastic tank blew on the radiator. New radiator and new 195 tstat and it is running cooler. Even replaced the tstat with another tstat and still the same. I know in my case, the radiator was a little clogged (usually around 210 when warmed up).

 

My theory is that the temp sensor for the gauge is a little off. Best bet is to measure the temp right at the tstat housing. Mine seems to be running around 180 and right now it seems fine so I have left it alone.

 

If it is really running too cool, your gas mileage will suffer.

 

//90GMCZ71

[Deserthigh]

Ref: 1986 GMC3/4ton 4x4..California Stock

 

Just dropped in a new radiator and thermostat. Stayed with the 195 thermostat. Before the swap out it ran at 210 all the time after warm up. today it ran at 160-180.. should it not go on up to at least 195? Pretty sure the thermo is in with the spring down...exact same radiator as the old one...but the old one may have been clogged...

 

so..does the 195 usually register 195 on the gauge or was 210 degrees what the 195 should result in? Wfhy would it be running so cool now? finally, is 160 -180 to cool for a 1986 choked nearly to death with emission controls?

 

Same thing recently happened to me. 1990 GMC 5.7. Plastic tank blew on the radiator. New radiator and new 195 tstat and it is running cooler. Even replaced the tstat with another tstat and still the same. I know in my case, the radiator was a little clogged (usually around 210 when warmed up).

 

My theory is that the temp sensor for the gauge is a little off. Best bet is to measure the temp right at the tstat housing. Mine seems to be running around 180 and right now it seems fine so I have left it alone.

 

If it is really running too cool, your gas mileage will suffer.

 

//90GMCZ71

 

 

 

That's my story..was 210 now 160 -180, runs better it seems, as long as it is not too cool i'm good with it, heater still blows hot. It was pretty d**n hot in the cab in the summer what with it running at 210 degrees, A/C disconnected, does not get all that hot here in central oregon...I'm going on a long trip up to central washington this next week, I'll see how the gas milage goes, could it get any worse than 6-9 mpg?