drcoopster

So it's winter this week, and I mean winter here in New England. And when it's cold like this (~10°F), I have no heat. Zilch. The car simply doesn't warm up enough during my 30-40 minute drive (75% highway by time) to give me any heat.

Any suggestions?

NZConvertible

Replace the thermostat with a new one from Mazda. It sounds like it's stuck open.

SureShot

Old school trick - block off half the radiator with a piece of cardboard.

wozzoom

I had this problem on some cold sub-zero nights here in PA. The car will just not get warm, especially on the highway at 70mph. My temp gauge would never get above the first line marker.

You could replace the thermostat if you don't know the history of it, but that may not be the problem. You could also put a 195 degree thermostat in place of the 180 degree stocker.

Aaron Cake

iTrader: (1)

If your car is not reaching operating temperature, then something is wrong. The thermostat stays closed until the engine warms up, so the ambient temperature is not a concern. The rotary is such an efficient heater that the car should be warm after about 5 miles or so.

First step is to make sure the thermostat is working, and that the car is filled with the proper water/coolant mixture.

wozzoom

Haven't you ever had a time up in cold *** Canada where the engine never got warm enough to open the thermostat? I can think of two occasions here in PA where the temp was -10 degrees and the windchill made it even colder. I was driving on the interstate at about 70 mph and the engine never got warm. The needle on the factory gauge just sat below the first line... The next day when the temps got back into the 30s, I had no problem.

I agree that the owner should verrify the thermostat operation, but sometimes it's just real cold out!

Aaron Cake

iTrader: (1)

Never. Even in -40 degree weather, the car is always at operating temp by the time I get to the office (about 3 miles).

That's very odd, unless the thermostat was stuck open.

drcoopster

I don't think it's worth it to replace the thermostat at this time; I'm leaving for Texas in a few days and will be there until mid-May. I think part of the problem is that my heater valve is stuck wide open and I have to have my defroster on to keep the windshield from fogging up. I do try to keep the blower on recirculate so that I'm not drawing extra-cold air from outside through the heater core, only the cold-but-not-quite-as-cold air from inside the car. If I keep the blower as low as possible for a little bit then it warms up after maybe 15 minutes.

I think I'm just going to have to chalk this one up to cold weather. Besides, if the thermostat really is stuck open, that's not a problem once I get to warmer weather. And once I get there, if needed I can replace it, I have one sitting in my toolbox that I bought over the summer as a safeguard.

Thanks for the replies.

FWIW, my late departed Volvo wouldn't get warm for about 20 or 25 minutes of driving last winter when it was hovering around -15°F, and the thermostat was in good working order. It was just wicked cold--cold enough to freeze condensation inside my intercooler and block it up, leaving me stranded at work! (Now that was annoying.)

jon88se

Thermostats stick people and parts store pieces tend not to last as long as OEM (these ARE old cars, I doubt many of them had original mazda thermostats when you purchased it). You should make it a part of your annual maintenence...coolant flush/fill and a thermostat. Both of which cost you $20 and 40 minutes of your life. I replaced T-stats in the GVR4 and the FC a couple weeks back. The GVR4 had a ralliart t-stat in it (180, stock is 195) and it was stuck open. $7.00 for a stant from pepboys and a gasket and now my car warms up quicker and has better heat than before