my m50 is running too cool?

[ian325is]

I put an m50 from a 93 325is in my 84 325e. Since then i havent been able to get my temps up from the 1/4 mark on my gauge. I checked my coolant temp today in my resevoir and it read 180.... i read that operating temps are between 180 and 220. I assumed before i started playing with all this that it was cuz i had installed my fan to run on high all the time. I fixed this issue and at idle my gauge is solid in the middle but as soon as i start moving temps drop and stay steady at the 1/4 mark. Currently im running the e36 radiator and fan. Im not so worried that my temps are out of range but that my guage is 'off'.... id feel a lot better if it was steady in the middle... i was thinking this was a thermostat issie until i started looking at them and found that oem thermostats are 180 deg... should i look for something higher? Should i say to hell with it and just leave it alone? Im interested in anythoughts and opions on this.... coolant temp gauges are already a hassle with a stock e30 but now that ive thrown an m50 into the mix im out of ideas and figured i would turn to the pros on here... thanks in advance

[DesertBMW]

only way that it would run too cool is if thermostat is always open

[mitchlikesbikes]

thermostats are designed to fail open, so chances are you need a new one if you're actually running too cool.

have you verified temp with an infrared gun thermometer? the gauge on my jeep reads a solid 10-20 degrees high. my e30s is closer to actual temp but they are almost never 100% accurate.

[Thebrab]

^^^X2 thermostats on m50s go bad a lot