Guys I've got an 06 mini convertible and I can't get it to stop overheating. I've replaced thermostat, bled the system and put a new cap on it and none of that worked. I checked the radiator for rust and build up and it seems fine and the water pumpg is not leaking or seized. When I bleed the hoses it's nothing but steam!! The fan does kick on buy as soon as it does boom it starts to overheat. What are my DIY options from here?

 

105.C low speed fan kick on, and 112.c high speed fan kick on.
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you can use instrument panel to check temperature, just like this: http://dabongmini.blogspot.kr/2013/0...cooper_15.html

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if high speed fan is ok. you must bleed the coolant. there is air in coolant system.

the easy way to bleed is:
top up coolant and then start engine. watch water temperature, when temperature is between 90 and 105.c, turn off engine. I think the temperature 95.c is better.

wait until engine is cool. or over night.

if coolant in expansion tank is low , top up coolant again and then start engine. watch water temperature, when temperature is between 90 and 105.c, turn off engine.

repeat....until you find the coolant in expansion tank doesn't lower then top up..

 

air540G: Do you mean to suggest in your first step that the coolant tank cap remains off during what you describe? And, what about bleeder screws? I've taken my cooling system apart several times, and never had a problem bleeding the system, but it involves opening both bleeder screws.

 

r50/52 cooling system is very difficult to bleed.

after using bleeder screw to bleed, you must follow my describe to bleed again.

close the tank cap.

our car thermostat opens at 90.c.

turn off engine when coolant temperature is between 90 and 105.c. top up coolant in coolant tank, let coolant level over max. and then let engine cool down.

after over night, the coolant level in coolant tank will be lower then min. because there is air in coolant system.

so, top up coolant again.......

until the next day ,you find coolant doesn't lower then top up. It means no air in coolant system.

 

Did you replace the thermostat to fix an overheating issue or did it start after you replaced the thermostat?

Did you use an OE thermostat? Did you buy an aftermarket housing that could allow you to install the thermostat backwards?