Hey fellas, how is it going? D-Day approaching.....

I've decided to purchase an 180F thermostat. My old on is still OK (just 3 years or so) but it still keeps my temp of the engine a little too high at idle and after off road, like 205F. So i'm waiting for the new one, it's a Stant 48718 XACTStat 180F.
Will also flush the engine cooler and , with my brand new cooler installed few weeks ago, hope the rig runs at stays at 180F / 85-90°.
I'll give some news soon about it.

 

Why pick 205* F as too high????? GM intentionally set the operating temp for H3s at appx. 200*F, 205 being a bit better for reduced emissions.

Kinda like changing a light bulb that still works.

Let us know how it goes.

 

Unless you reprogram the ECM or PCM (depending on year), the 180° thermostat will do nothing. The computer will try to do everything it can to reach the predetermined running temp set up from the factory.

 

I have a reprogrammed PCM from PCM of NY since years now, for better power + torque etc, so i'll see what it does and if the temperature stays stable. Even if stays around 190 would be good, as long as the temp doesn't move up and down, like it actually does.

And have a nice Remembrance day, over here Luxembourg and France will have military parade. Can't go to the parade, i'm on duty ...

 

So the new thermostat is in and all seems fine. Drove over 60 miles around, highway and town mix, temp stays stable 185F, perfect.

 

Why change over 100yrs of engineering?

Engine coolant temperature has an ideal temperature for engine operation that is normally between 90-100 degrees Celsius or 194-212 Fahrenheit. At temperatures lower than this the control strategy must be modified to ensure stable combustion, generally at the expense of fuel economy and hydrocarbon emissions.

 

Thanks for info. Today I tried another mix, first drove about 100 km highway, then i made a 35 km off road trip. Then i return home by taking normal roads, driving 50, 70 an 90 km/h. Arrived home i let the engine turn at idle about 20 minutes. During the trip i connected my OBD reader and watched temp on dashboard. It stays at 92°C and the temp on dash did move, just a littlelittlelittlelittle above the middle. At home, after running 20 min at idle the temp goes to 95° then back. No error codes, no lights on and engine is running well.

 

You're missing the point. The quicker the engine gets to 91 Celsius/195 Fahrenheit the better! Your current thermostat opens at 180F so it will take longer and the engine will stay in lean mode to get the temp up. Waste of fuel and more carbon will occur, which affects many components.

Live and Learn:

https://www.carbibles.com/car-thermostat/

 

Thanks for that. In fact the temperature get real quick to the middle, don't have to drive much miles around for that. Gonna have a 620 Km trip on Wednesday, lets see how it cools and heats.

 

Hey Guys, back home and the new thermostat did it's job well. There was lots of traffic and we had two times, like 20 miles stop and go traffic. The temperature never gets over 100°C during all that and as soon we drive it stays at 93°C. My H3 drove those 625 Km with no issue.