Having an issue here and I'm not sure what I should do.

My wife said that the fan on our 06 mini was staying on after she shut the car off and that it was crazy loud, like a big hair dryer. I told her to come home and I would see what was going on. The coolant was empty and I accidentally filled it without mixing the BMW coolant with water.

When we are at idle for more than a few minutes the car kicks the fan on loud and will start to overheat after about 5 minutes and then eventually it will hit the top of the heat gauge. If we start driving at any speed above about 20 MPH the heat gauge goes down to the normal halfway position.

If we are at idle or driving real slow the heater will turn to cold. If we speed up the heater will kick back on to the full heat.

I've searched all around and there are no leaks that I can see.

Could the issue be related to the fact that I put 100% coolant in instead of the 50/50 mix? Do I need to drain the coolant and put it in at 50/50 like the bottle says? If so, I don't know how to drain it.

When I turn on the car the fan by the radiator is not spinning. When I hear the first loudness the fan kicks on. When I hear the very loudness it is still on.

I live 2 1/2 hours from the nearest dealership and I'm off warranty, so I was hoping I start here fist.

Thank you very much for any help.

 

Coolant that is not diluted does not transfer heat as well....so one issue...How much did you add? IF it was only a quart or two, it should be fine.

I bet the coolant was just low...it may have sucked some air in, and has a bubble in it....this can cause it it overheat. It needs to be bled a bit...and have more properly mixed coolant of the PROPER TYPE ADDED. ALWAYS USE DISTILLED WATER TO WATER DOWN COOLANT...NEVER SPRING OR TAP WATER (the minerals it it will precipitate out and for "gunk")!!

Why was it low?
...there are several common leaks...the tank on the S tends to leak around the seam, and the thermostat gasket/housing is common...the thermostat could be bad...but when you replace the gasket that leaks, a new thermostat is attached...
Could you have a minor leak in a hose, or in anyone of a million places...yes...you need to look...Diagnosing a car by forum is kind unwise, and can be costly. We can tell you the most common things to look for...
The Fan on the MINI tends to have one of 2 speeds fail too...the low speed fails...many threads on it...it is likely why it sounds so loud...the fan should run on low speed (quiet) then switch to hi if the temp keeps going up. Warning...this item will not cause the issue you are having...but it MAY be broken.

 

check
https://www.northamericanmotoring.co...-solution.html

 

Checked it all out and I can't see a leak anywhere. I'm not going to risk it and I think I'll call our local BMW guys and see if they are able to work on off warranty mini's. If not, I'll be making quite a trek, but as I said, all works fine if I'm going fast enough, so I think I'll make it all the way without a problem.

 

With just a coolant leak any garage that works on european vehicle should have no trouble figuring out what is going on.

 

+1
at about half the hourly cost...
With a BMW dealer, you will be paying the guy to learn about your car...
At a good 3rd party shop, you may have an experanced tech that has already worked on a mini!!
The parts cost will be much less too from a 3 rd party...
An example...radiator cooling fan, about $85, but at the dealer 275$...some things are less, but even oem parts at non dealers are typically less!!

 

As Mini's get up there in age, the radiator can fail where the fins crimp to the Plastic side tanks...not likely on a 06', but anything is possible.
Most of thses leaks are pretty small...barely a drip...that grows overtime. Could even be a waterpump seal...someone just has too look for residue from the lost coolant.
The car sounds ok right?
If you noticed a marked sound change..like a chain-dragging or a metal grinding sound...then it might be something different...speed hel

 

I think I'm having the exact same issues! I've only noticed since the last time I had my oil change, maybe the mechanic did the same thing with the coolant.

I'm interested to know if you've solved the problem. I think I'll be going to my mechanic again after work and seeing if he can solve it. I know absolutly nothing about my car yet, and it's WAY to cold outside to poke around under the hood for me so I'll let him do it.

 

I had my thermo/gasket replaced on my car once under warranty and then again probably around 80 or 90k. This year I had the heater hose replaced. but I had a leak both times.