40,000 KM! How many hours has it ran, and what work have you done?
I've got half that mileage on my 05 650. It has no fan, and has never boiled over. It gotten plenty hot a few times, but it was at 100°f (38°c) and was during an arduous slow off-road hill climb, or the 5 minute wait at the traffic lights.
I usually just shut it off if I have to wait for a second signal, but I usually just filter to the front.
Someone had asked what coolant you are using, but you haven't given it up yet.
Please tell, and include the ratio you are using.
I don't think bushie was referring to Evans coolant, but it's not waterbased, and doesn't boil.
It doesn't necessarily keep it from overheating. It just won't boil.
Im using Pentafrost SF (silicate free). It's pink, and specced for German cars. I use it 30%, and 70% distilled water. I also use a few capfuls of water wetter.
Water is the best for transferring heat, the ratio I'm running is working for me because it's mostly water.
I don't remember the freezing point of that ratio, I checked it with a bulb tester, and iirc it was around 10°f or minus 12°c.
At 50/50 it's -38°with 109° boiling point. Got that info here:
http://www.pentosin.net/pressreleases/C ... t_SF_2.pdf
Additionally, I've removed the thermostat and fitted a return hose from an FC model. It's never had a problem warming up, but doesn't get too cold here in California
You could do the same, and for cold temperature riding block off part of the radiator with tape or cardboard if necessary.
You might check out the condition of your radiator aswell. It needs a thorough cleaning every so often to be able to transfer the heat properly. Not really sure, but white vinegar might sparkle it up without harm. Just rinse it thoroughly when finished.
Also, could you please post a stunt video?
