Hi guys -

I've got a 2005 Cooper with about 25K miles on it, almost entirely city driving. I live in a hot climate (New Orleans), so I'm used to hearing the loud fan running after I cut the engine on a hot day. As long as the temp gauge isn't showing that the car is overheating, I figure the car is just doing what it's supposed to do. I almost always drive with the a/c on.

About twice a year when the weather is hot, the temp gauge will show the car heating up, along with the fan running loud after I've cut the engine. When that happens, I pop the hood and usually find the coolant tank completely empty. Last year, this happened only one day after I'd had the car serviced at the dealer, so I guess they didn't check fluid levels with the oil change. Anyway, each time I refill the coolant tank, the temp goes down and the fan doesn't run loud as often. In the summer, the coolant lasts about two months, but I've never had to top it off during cool weather. When the car is running hot, if I turn off the a/c and turn the fan up to high so it will blow heat off the engine into the passenger compartment, the temp gauge will drop form high to about half-way, until I get it home and can top off the coolant.

So, the weather is heating up (I live in New Orleans), and the fan has been running loud, but the temp gauge is fine so I didn't worry about it for a few days. Two days ago the temp gauge shot up, so I checked the coolant and it was empty. I added coolant, everything went back to normal. Today the temp went back up, and the coolant tank is about 3/4 full. So I'm losing some coolant somewhere, but the car still has enough that it should be cooling down.

Writing this down, I can tell I'm screwed. I know, I should routinely check fluid levels, but honestly, that's why I take the car in for routine maintenance, so I don't have to worry about that crap myself.

So my questions are: 1) is it normal to have to add coolant periodically, or has it been leaking all along? I'm pretty sure the '03 I had before this one did the same thing, so I thought it was just a Mini quirk that I needed to add coolant occasionally during the summer. 2) Since I hear the loud fan after engine is off, is it likely the low speed fan is blown out, or is the fan just running high because I've been leaking coolant? 3) Since this has been a pattern for almost five years that I've owned the car, should I assume that something is seriously f'd and start shopping for a new car? The Mini dealer is an hour away in Baton Rouge so it's a hassle to get there, and I'm not at all confident that they won't screw me on repairs given the opportunity.

Thanks for any advice
- Nola

 

In my experience it is difficult to make judgments about the health of your cooling system based solely on the level of coolant in the expansion tank. On mine at least that level varies considerably depending on coolant temperature, ambient temperature, and perhaps other factors I don't appreciate. Before proceeding any further you should make absolutely certain that there is no air in your system by bleeding it according to recommended procedures. Also, every night park the car in the same place, over an unstained floor, and check the next morning for any evidence of a leak.

 

My wife's 06 MCS was doing the same thing. Like yourself, we live in a hot and humid climate, Daphne, AL, so we take our A/C issues seriously.

It was my search through NAM that led me in the right direction. It sounds to me like your thermostat housing is leaking. The leak is enough to lower your expansion tank over time but not leave puddles wherever you park. I was finally able to verify the leak with a good flashlight and a cold engine. The gasket area around the housing was showing areas of dried coolant.

I got a new housing (a new thermostat since I was going in that area anyway) and did the fix myself. Since you have only 25k miles, you should be able to get it done under warranty. I've dealt with Brian Harris and they always treated me well.

I have not had a problem since. The temp gauge hardly varies, the high speed fan does not come on as often and the coolant level is solid.

 

Two simple things to look for...the coolant tank should be a yellowish milky color....the orgional factory ones, the clear ones leaked aroung the seam very quickly....the newer ones, replaced underwarreny in most cases are better, bur can still leak. Look for whiteish residue around the seam of the tank.
Next, the thermosta often leaks on the 05's, so that may be an issue...the newer part has a better gasket.
Either one of these issues will cause your car to consume coolant...and both are fixed very easily....and comparitivly cheaply. You also likely have a bubble or airlock in the cooling system from having run low...when the problem is fixed, bleed the system...fresh coolant may be a good idea too. Any car will run hot if there is not enough coolant.
The fan operation is a bit of a seperate issue...if the low-speed has failed, the new fan is about 85-90$ if you get a good aftermarket one, and a couple hours labor to instal it or diy it.
Both of these very common coolant leaks are easy to fix...cheap, and match the loss rates you are seeing. If you had more miles, then I would also look at the weap hole on the water-pump, but check out the first 2 things first!!
Enjoy your car....it sounds like it is fine ( or will be with a bit of TLC)!!

 

Yes! The coolant tank seam. I had that happen to me on my 03. I had forgotten about that little experience. Good call ZippyNH. I agree with ZippyNH.

 

I just had to buy one for my 03. I noticed the green juice on the heatshield under it. After hosing everything off to make sure it was indeed leaking (the seam was wet after a couple days of driving) I ordered it up.

Looks OEM, got it in 3 days. YMMV

http://www.partsgeek.com/catalog/200...sion_tank.html

 

y'all rock. Thank you!