Trying to be a 'do-it'yourselfer'. Time to change the radiator coolant. There should be 1 1/2 gallons of fluid. I released the lower hose on the radiator and let out the fluid, but when I refilled only a half-gallon went in. Is there an engine block drain plug that I missed? I can't find the bleed screw on the thermostat housing. This is on a 2004 Cooper S. Advice?

 

You're asking in the wrong forum...

 

My Mini is still on order, so I'm not too familiar with them, but I'd guess that you were on the right track with looking for a bleed screw (although I doubt you'd find one). You've probably got an air lock in the engine block because the thermostat is closed.

The Bentley Service Manual is probably a wise investment: http://www.motoringfile.com/2004/09/...now_available/

It would certainly cover the proper procedures for coolant replacement.

 

On the pre-'07s, the block drain plug is located above the starter, behind the engine. It's in a royally tight and inaccessible place. I fitted a temp sensor in that location. The only way to successfully do that was to remove the exhaust header and heat shielding, which is not a difficult job overall. You'll need to have the header flange and exhaust pipe gaskets as well.

When refilling with coolant, you need to bleed the air from the system. The air bleed is in the upper hose. Fill the reservoir, run the engine, loosen the bleed screw till coolant appears, tighten and add coolant as necessary. Repeat this a couple times. Do this with the heater on as well.

 

Sounds easier to pay someone to do it

 

Moved from 2nd Generation to 1st Generation Forum.

 

There's a second bleed screw on the MCS. It is on the thermostat housing and I believe it is a 10mm nut. I learned about it after doing my first coolant change. You should be able to see it if you look down on the right of the intercooler. Like you, I was bewildered by the fact that I didn't have to put much coolant back in. I ended up also having an airlock since I didn't know about the second bleed screw. Once you get coolant in the upper hose, you should be fine. The system can easily be bled with the plastic screw in the upper hose from there.

 

resurrecting this thread...

upper hose is the one just above the radiator right? and the air bleed screw is the one on this one?

if i fill via the upper hose, do i need to deal w/ this 2nd bleed screw?

 

yes. There is another one near the thermostat. Look down just behind the driver's side upper corner of the intercooler. I think it is an 8mm head screw.

Fill the system with these screws open and close them when coolant comes out. This is with the car off. Heater position doesn't matter. I know poeple will say different, but they must not know how the system works. Once the reservoir is full, loosen these screws and recheck for coolant flow and close them. Do not over tighten it. It will break, maybe even down the road sometime. I see this at the shop occasionally. Now run the engine until it heats up and top of as needed. Double check the level after it has competely cooled. If you do it this way it will be fast and easy. I have done it this way many times, infact last weekend, and I have never had an issue.