Time to open thermostat in cold weather

[Weazel]

Kind of a dumb question, but here goes. I just tested my coolant yesterday, and it was good to somewhere between 0 and -5 degrees. It's gonna be colder than that up here in a few days (yay) so I took a gallon of coolant out, and put in a gallon of antifreeze, so the mix should be good to -25 or so. I wanted to make sure that it mixed, so I idled the car for about 40 minutes while having dinner. The temp gauge I have is really unreliable, but it went up to an indicated 200. The car usually cruises at 210 or so on that gauge on the highway in summer.

I couldn't hook up direct scan, and I'm not absolutely sure whether it has the stock thermostat or a 160 degree one. I just know that DS usually reads 170ish while cruising,and 190 if I'm in the staging lanes.

I just wanna make sure the coolant from the engine mixed in with that of the radiator (where I added the new coolant). I let it idle forever, but that was at a 15 degree ambient temperature. Now the thermostat has always worked before (car never overheated) so it would've HAD to cycle the coolant in the time I was idling it...right...??? I'm an idiot, I thought the mix was fine until I tested it just now, of course RIGHT before the coldest day I've ever seen. Just looking for some input, thx.

JLW

 

[salvageV6]

Since I assume you can't or don't want to drive the car a bit I would rev it up to 2500 or so rpms three or four times for 10 seconds.

Flows a lot more at that rev according to my see through plastic T I use to cool my turbo.

Otherwise just drive it 6-10 miles.

I would assume stock thermostat at those temps. and it should be open.

 

[salvageV6]

In a pinch to verify your thermostat opening if you have a scanmaster you should see a quick 15-20 degree drop upon initial warmup of the car.

Or you might have to hook up direct scan to watch it live.

Probably won't register on a gauge since it's quick and not a huge swing.

 

[BJM]

If the thermostat is open the upper radiator hose is quite hot. You will also see fluid pouring out of the tubes when the cap is off. I do all my warming up after changing coolant with the cap off so I can see everything. Rev it and the flow is quite obvious.