I have a 2003 mini nonturbo and it overheats when I slow down , even on cool days . How do I get all the air out of the cooling system ?

 

The coolant is added to the car at the thermostat neck on the engine. Before you start to fill the engine, loosen the vent screw in the plastic coupler piece coming from the lower radiator hose as well as the vent screw in the distribution pipe on the rear of the thermostat housing. Also turn the ignition of the car on (don’t start it just yet) and set the heater controls to the maximum level with the fan on low. This will open the lines going to the heater core inside the car.

Because of the position of the thermostat under the filler neck, adding coolant to the R50 can be a little difficult. What will help considerably is a filling kit that works off gravity. This kit (Lisle 24610) allows you to attach a large reservoir to the filler neck using a series of adapters. Once attached, pour the coolant into the reservoir and let gravity do the rest. You’ll want to fill the engine until you start to see coolant coming out of both vent screws. Once you see this, close both of the screws. Keep filling the reservoir until it no longer drain into the filler neck. Now remove the reservoir and close the vent screws.

With the vent screws closed, continue to fill the engine until the coolant level reaches the inner ring of the filler neck. Now put the pressure cap back on the filler neck and fill the overflow tank on the rear bulkhead to the MAX mark. Now start the engine and let it idle. You’ll want to keep an eye of the coolant level at the overflow tank. Top off the coolant in the tank until the car fully warms up and the coolant level drops.

http://www.pelicanparts.com/techarti...ant_Change.htm

 

Vic, are your radiator fan coming on when you slow down? The car will cool well enough at speed, but if the fans aren't working, it will overheat when you slow down.

 

I recently replaced my radiator fan. They have a design flaw where the low speed of the fan stops working, but in my case my radiator fan didn't work at all.

I found this out because my coolant boiled when I was stuck in stop-and-go traffic. seeing white smoke coming off the top of my hood. When you're going sufficiently fast, there's enough moving air to cool things down without the fan.

I would first check to see if it's the radiator fan. The surefire way to see if it activates is to turn your AC on to maximum and then observe if the fan ever actuates.

Replacing it isn't super hard, but you'll lose some coolant and it took me a couple hours to figure out how to get the old fan out.