engine temp and thermostat questions

[ahardb0dy]

I know this has been covered in different topics before but wanted to start my own thread to see if I can get some answers to specific questions.

 

On my 94 PF, have a JDM engine installed in it, truck runs fine, have the (seems to be normal) low reading temp gauge, it sits about a 1/4" or less up from the bottom at all times. Grounded out the gauge sender and it went all the way to hot so that means the gauge works, Started the truck and let it run for about 15 minutes, had the air relief bolt out the whole time and had a temp gauge stuck in the hole, the only time coolant would come out is if I revved the engine a little, temp never went over 120 degrees at this point, shut the engine off and with a thick towel removed the radiator cap, no sound of pressure came out, no coolant, in fact the radiator cap felt cool, topped off the coolant and started the engine again. Checked the temp in the radiator with the same temp. gauge and it went up to the same about 120 degrees. Not sure if the thermostat finally opened but the temp of the coolant at the air relief bolt hole went up to a high of 140 degrees, but that was right before the time I think the thermostat opened, a few seconds later the coolant temp was back down at or below 120 degrees. Couldn't really tell if the coolant was circulating by looking inside the radiator, the upper rad hose didn't feel real hot, the heater hoses felt hotter, Oh I flushed the heater core out before doing any of this, some rusty water came out for a few seconds than it ran clear. Heat at the vents is warm but not "burns your hand hot" as members have said theirs gets.

 

I Have a new fan clutch and have never replaced the thermostat, may pick one up later. Should coolant come out of the air relief hole at a steady rate normally?

 

Thanks, let me know what you all think.

[XSrcing]

I don't know about the temps you are reading, but when you opened that bolt, you released all the pressure in the cooling system. That is why when you removed the radiator cap there was no hissing noise.

[RustyButTrusty]

My dad has a 95 model, and during winter months the temperature gauge barley moves. The heater gets plenty hot, and gas mileage stays the same. During the summer months with the A/C running the temp gauge can get up to about halfway between hot and cold. Maybe these are just cool running engines

[Tungsten]

either the gauge has a problem or your thermostat is stuck open

the temp should be consistent throughout all seasons

[ahardb0dy]

I don't know about the temps you are reading, but when you opened that bolt, you released all the pressure in the cooling system. That is why when you removed the radiator cap there was no hissing noise.

 

 

makes sense, didn't think about that.

[adamzan]

If your heat is not burn your hands hot in Florida, you have a problem. Even here in Canada in -30 (sometimes) the heater gets really hot. I had the lukewarm heat thing before and a new thermostat fixed it.

[ahardb0dy]

went up to the auto parts store earlier to get a thermostat and they had just closed 20 minutes before, so will have to wait until Sunday. Will post results after I replace it, thanks