The thermostat was getting worse, not only it took quite long time to reach 80, but also after it reached 80, it went all the way to 110, I had to turn on heater to cool the engine.
Ordered a 80 C thermostat from Partshop, but just couldn't wait for a week.
Yesterday I took out the old thermostat, and brought it to local Canadian Tire store, I was very lucky to find a one with the same diameter, the gasket fits perfectly. It's a MotorRad brand high flow thermostat, only difference is that it's 192 F (90 C), and it cost only 22 Canadian$ (14 USD).
Now the engine warms up super fast, and the needle stays one line above 80 degree, I guess it should be 90 C.
Can I use this 90 C thomerstat for this whole winter and use the OEM 80 C when it gets warm? An extra 10 degree makes me feel warmer in Canadian winter, I hope this M119 engine is not very sensitive to coolant temperature.
BTW, the original thermostat from the car was very bad, I easily pulled out the center push rod by my hand.
99 BMW 540i 6-speed 110K Km
03 SAAB 9-5 wagon 80K Km
92 400E (Sold) 245K km
Still missing the days with the Benz, it kept me busy.