After a month or two of cooler temps, I've noticed that the heater was not warming me up enough. The rtek shows 155F engine temp on average which is below the desired temp. The gauge in the dash just barely goes above the C mark which would normally read 1/4 in my other RX-7s.

To test the thermostat, I boiled up a pot of water and checked to see when the new thermostat (been in the car for over a year) and the original (which happened to be from a spare motor) would open.

As the water warmed up, the new thermostat started to open around 145-150 degrees. The OE t-stat started to open around 165. Both are stamped 82C. The temp is at 185 in the picture below. New t-stat is open all the way and the OE is open, but no where near as much. I think the new t-stat is miscalibrated. Ever since I put it in, the car ran cool, but I also put a new radiator in at the same time so I figured it was doing a decent job.

Has anyone else had similar results with the new thermostats from Mazda? I suppose it will be a good summer t-stat for another car. :P

 

I got a couple from Mazdatrix that I thought were stock, but they all were controlling at ???? 165*or so. WAaay too low. So I went to AutoZone and bought a 185* aftermarket thermostat......for a couple of cars to replace the ones from Mazdatrix.

I authored a thread on this mistake of mine, a year or two ago.

EDIT: And the RTEK mirrors the 185* the new aftermarket thermostat works at.

EDIT to the EDIT: and neither of the thermostats from Mazdatrix had any operating temperature stamped on them nor did the little white box have any numbers on it.

 

How can Mazda stock thermostats that are out of spec? Kind of a disappointment really. I plan on putting the OE back in to get the temps where they below. I've very confident that the thermosensor is correct because it reads temps that match that from the stock gauge as well as my aftermarket temp gauge, 3 for 3. How far is the OE thermostat supposed to open max?

 

sry to bring back an old thread but, i have a similar question,,,,goin down the highway my temp according to my aftermarket temp gauge runs at like 160 to 170 and the only way it will warm up is if i let it sit and idle for a while and i have my aftermarket efan set to come on at 190 so it stays around that range untill i go drive then it goes back down...wat would cause this..its a stant thermostat but its supposed to be 185 i think...also im getting like 12 mpg