When I initially started this thread, I was in the process of swapping out the cheap 195 thermostat for a Duralast 180 thermostat that I replaced because I thought the lower temp thermo was responsible for my lack of heat, before I found it was due to low coolant because water pump was going bad.
While I had both thermos out, I decided to put them in some water and make sure they open when they should and are closed when they should. The 180 thermo didn't open til the water was past 180, I think 190 or 195. The 195 didn't open til well over 200, like 210. So I don't see how my engine wasn't getting warm, it definitely couldn't or shouldn't have been due to the thermo staying open. Under the impression that the heater core was toast, I put everything back together, using the 180 thermo. I mean why not, what's the worst that could happen, right?
So, I put the 180 thermo in, put coolant back in and start it up so the coolant can circulate and I can top the radiator off. After letting it run for a few min, I check the temp guage and the needle moved further then it had for a 10-20 min drive!!! So I turn the heat on and
VOLIA!!! I got heat!!! Well not take your clothes off heat, but I wont chatter and mess my teeth up for 10-15 miles.
I still think I may need to replace my heater core, however. And I may look into a temp sensor as well.
Your engine IS getting warm.. If the thermostat is stuck open, then it will take a LOT longer to get to operating temp.
How about never. The day after Christmas, I drove about 350 miles, from St. Louis, MO to Junction City, KS. Engine did not reach operating temps after driving almost 6.5 hours at 70mph. Same thing on the way back.