Running temperatures that low is ruining you engine! You are not running hot enough to even evaporate the accumulated condensation in the engine. If your thermostat is not opening and you still cannot get the temps up, the engine is being cooled some other way - probably your
oil cooler (if you have one) or your heater. If you have an
oil cooler, you need to either install an
oil cooler thermostat or cover up the fins.
You don't want to run your engine at less than about 190 degrees. Defective thermostats are usually the culprits. There are tons of good posts here on how to test a t-stat.
Good luck,
Brian