I posted a couple of days ago with my tale of woe: New thermostat, still takes 20 minutes to get some heat, temp gauge never goes above 1/4, except on the highway it sometimes approaches 1/2. Last year the gauge seemed to be at 1/2 most of the time, although it still took a long time to get heat going.
Picture of thermostat housing showed a large weep hole:
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Today on the way to work I stopped at the Saturn dealer, asked to see a thermostat housing. A look showed that the weep hole is supposed to have a tiny ball bearing in there, with a piece of metal pressed in to hold it. The bearing acts as a check valve. I could not blow through the outlet pipe, whereas with my housing I could blow through it with very little resistance. I knew I had the answer, bought the housing (which comes with a thermostat). I put it in tonight. Took the car for a 5 minute test drive, gauge comes up to 1/2 and heat is wonderful. And it is cold out, I would guess 20 degrees. (I have a heated garage to work in)
Googling back in the group shows that many people have had heating problems, I would bet dollars to Krispy Kreme doughnuts that this was the culprit in many of the cases.
Good news: I have heat Bad news: I now own a lifetime supply of Saturn thermostats. Also, that tiny ball bearing is somewhere in the cooling system of my engine. Probably lodged in the radiator I would bet.
-David