Hey all, it's that time for me MINI.

I'd like to hear from anyone that has flushed out the coolant system on their MINI, tips would be great. I don't recall seeing a plug under the radiator like on most cars, but I could've missed it.
Also, I'll be refilling with Redline's Water Wetter, but not sure with which kind of Coolant to mix it with. thanks in advance

James

 

It's that time for me too. I haven't heard much but I believe the MINI doesn't have a drain bolt so you drain it by removing the coolant hose at the bottom of the radiator. A standard 50/50 mix would work with Water Wetter as it will just bump the thermal conductivity up to that of pure water (with the added benefit of the antifreeze).

 

Flushed mine last December. I removed the Moss skid plate and then with a pair of vise grip plyers disconnected the bottom hose leading into the radiator. Released the vacumm and let it drain. Reconnected the hose. Once drained filled it up with a 50/50 mixture. I stayed away from the regular brand of anti-freeze and purchased 1 gallon from local BMW dealership. Drove around the block and then bled the air in the system out. This needed to be done several times, as the air pockets worked their way to the top. There is a little valve on the upper supply line that allows for the air bleeding. Once it looked like it was completely full, I topped it off via the overflow tank. No problems. Good luck & have fun.....

 

right on kapps. I'm thinking of removing that plug on the top hose right in front of the intake manifold and running water thru the resavoir til it all flows clear, what do you think? Should we use a flush solution or anything like that?

I didn't think there was a plug on the bottom of the radiadotor as I've had the entire front end off before and knew when I did that I had to have looked for one.

 

My plan is to just drain from the bottom hose and fill through the overflow tank (unless I find an easier place). I'm not sure that a flush solution is needed since it's only a year or two old. Maybe once it hits 100k miles...

 

Beware running anything but distilled water through your cooling system. In many places there are LOTS of minerals in the water, and they will deposit on the aluminum components.

 

Thanks guys, I'll disconnect the bottom hose to drain the radiator too then. Got the distilled water ready to go too.

James

 

Or remove both hoses from the radiator wrap a shop towel around end of gardenhose & flush from bottom up.(that flushes all capallaries). There is a drain plug on the back of the block also.<if your truely ****). Premix your antifreese & distilled water (eliminates guesswork) Initially start the engine with coolant res. cap off & bleed screw on upper hose loose(top off coolant as both burp excess air) Drive, cooldown, restart & check both again ... Whenever topping off radiator or wiper res. use distilled water.

 

What's a common source of distilled water?

 

Grocery store.

 

Distilled water is readily available at any grocery store. Just be sure you don't accidently get a jug of MINERAL water! We want to avoid minerals if at all posible. If you can find ionized water, that is even better than distilled.

 

Ok guys, I've done the coolant and have a couple questions. 1st, after I took the lower radiator hose off, the radiator drained quickly but I only got less than a gallon of coolant out. I'm assuming the rest is in the block. The Bentley manual says nothing about draining the block so I just did the steps in the book. After filling the coolant expansion tank, the Bentley manual says it will drain into the system and then to close the bleed screw once coolant flows out...it didn't drain or flow out. Finally, I decided to turn the MINI on (with heater on high) and try to get it to flow. Once it heated up (with the exp. tank cap on), opened the bleed screw and got some air out. Drove around block and got some more, etc, etc until only coolant came from the screw. A success!

So now, I'd like to know why the Bentley manual says nothing about having the car on to fill the coolant and why I didn't get most of the 6 liters of coolant out in the 1st place. Does anyone have a picture of the coolant drain on the block? I'm assuming this is where the rest of the coolant is. I don't really like the fact that about 1/2 the coolant is still the old stuff.

 

I would think there would be a lot of coolant trapped in the block. There may be a way to drain it all, but that might also make it harder to get all the air out.

I overhauled a motor years ago and it took several days for all the air to work its way out. Nothing was going through the heater coil even though it was on full. After a few days, I heard it gurgling through the heater and it started working again.

I am not sure if the Mini would be the same or not.

I also have thought about flushing the old coolant out, but anything you use to flush will remain in the system unless you can get it all out. The only way to be sure you didn't leave hose water in the sysem would be to totally drain everything.

On my vehicles (my motorcycle is water cooled also) I drain and refill with fresh coolant more often than is recommended. I would hope that any resisdual old coolant would mix with the fresh and be drained the next time.

I had one car that came with dirty looking coolant from the factory. It took three drains and refils before it cleared out.

 

The amount of water left in the block cooling areas around the cylinders is generally a fairly small amount (maybe a quart maximum?). Some engines come with a nicely placed drain plug on the block to get out almost all of the water in it, but many engines do not. My MINI is only a year old, but next year I imagine I will do the drain and flush as I've done on other cars and as the others have recommended. With the engine off and the heater valve on, I reverse flush through the lower radiator hose (with engine off!) until the water runs clear, let drain completely, reattach hose(es), then add 50/50 mix, warm up engine, let it burp, fill, etc. etc. The distilled water for making your 50/50 mix is a good idea.

 

Wow, my VW had the long term fluid. I just assumed the Mini did too. So the radiator fluid for the mini is the standard every 2 years?

On my '87 BMW I took off the engine block drain and got it all out. I agree if you only do the radiator you are missing a bulk of the fluid.

 

To flush the coolant out of the block you should drain the radiatoir. Put the hose back on, fill totally with distilled water. Run engine making sure the heater is on and its up to operating temps. Drain again. Repeat until all coolant flows clear. Then fill with 50/50 and close it up.

 

If you do that you'll have a block full of water and it will be hard to get a 50/50 mix unless you drain the block as well. I just had the tranny out and I think the drain plug is tough to get to. Especialy without making a mess. For reference the one I saw was on the backside under the exhaust manifold.

 

All you have to do is add a bit more coolant to make up for the water in the block. It's not that complicated and doesn't have to be xactly a 50/50 mix.

Find out what the total capacity of the cooling system is, minus the radiator and you can figure out how much water is still in the block.