We're all familiar with the good old coolant tank issues. I had the tank replaced on my '02 within the first few months.

I've always seen traces of coolant seeping out from under the screw top. But recently there's a lot more of that, and more dried puddles on the heat shield below the tank. There's also evidence (tons of little dried drops) of coolant splattering around the tank. The screw top is on there pretty tight.

The last time I took it in, the dealer said that they "pressure-tested" the tank and everything is fine. Coolant is obviously still escaping though ...

Any thoughts?

 

My 04 S did this a couple weeks ago after I added coolant when the motor was cold. The coolant level in the tank was below the full line and I added too much coolant. I thought "no big deal" and left it. After driving the next day, I opened the bonnet and found the "splash". I cleaned it up and used my wife's turkey baster to remove the excess coolant(I made sure to clean up the utensil and sneak it back into the kitchen drawer). Since then, no problems.


2004 MCS EB/EB, Sport Package, Lapis Leather, 15% pulley, Alta intake, Miltec exhaust, MINI luggage, big smile.

 

I had this happening on my 04, reported it to the dealer at my 10k, they did something, and all has been good since. I told them I suspected the coolant had been over-filled after the JCW installation. They may have just removed the excess, like vegasdan.

 

The dealer may have pressure tested the tank, but hopefully they tested the cap as well. a weak or leaking cap can cause what you describe.

Also, make sure that the tank is never above the 'max' level when hot. Excessive coolant will purge via the cap. This isnt a cause for concern.

Make sure that your radiator fan is functioning. After driving a while, let the engine idle. The fan should come on periodically. Turning on the a/c or the defroster will engage the fan unless it is very cold outside. I suspect a lot of people are driving around (like I was) with a blown fan fuse due to the infamous power steering fan lockup issue. In normal driving you wont see a problem. It's only when sitting still in traffic with no airflow through the radiator that the engine will slowly begin to overheat. The temp gauge is only a minor help here, as it is designed to stay put at mid scale throughout a very wide range of 'normal' temperatures from about 180 degrees to over 230. It's only above that level when it will begin registering higher. By that time, the engine is quite hot and the coolant under quite a bit of pressure. This will cause occasional venting. People with Nav (like me) dont even have the temp gauge, and once the light is lit, about a minute later the engine WILL boil over. Then there will be coolant strewn about all over the place.

 

I thought I had a coolant leak but instead I had a air bubble in the system which caused coolant to spew out everywhere. The dealership figured that out and just had to bleed the coolant system.

 

I work for a UK dealer and any problems with this issue makes us change the header tank straight away under warranty...if u have warranty

The new header tank with come with a new cap

 

Interesting point ... I actually just got my car back a week ago. It had been garaged at our in laws for a month while we got situated at our new place.

When I've taken it out, it's felt different ... It sounds really "wound up". Right now, I can't tell if it's me not yet used to the new all season tires, or if the engine sounds different.

Checked coolant level, and it looks just fine (under the max line).

Eh, I'll take it in. My sunroof needs some grease anyway, so might as well.

Thanks y'all

 

My situation was like a couple of others on this thread. Coolant level was too high. Had to suck it out until it was just below the tops of the shark fins.

After that, no more coolant bubbling for me.

 

Note to self: Don't go to vegasdan's for Thanksgiving dinner.

 

Just today I noticed a mess of coolant on the heat shield below the resevoir on our 04. It looks like there is coolant seeping from the seams of the tank on all sides. I've never added coolant to the car.

Is this typical of a failing resevoir? It didn't look like it had been coming from the cap, but I guess I didn't look that closely.

 

Why does my turkey taste so sweet?

 

i have an 03 mini cooper and that i believe there is a anti freeze leak but i do not know where from there is no spilts in the tank. i believe its leaking over night when car is off from the bottom some where but not sure really where exactly and there isnt a mini cooper dealer around knoxville,TN and i dont know where to take it to get checked out

 

The cheap plastic coolant reservoir has a tendency to develop leaks at the middle where the seam is. Are you seeing any evidence of coolant on the heat shield below this reservoir, or does the leak seam to be coming from the front of the car where the radiator is?

 

They also tend to leak...hard to spot...around the thermostat gasket.....

 

I had the same symptoms with the white spots and all except i actually caught my mini in the act. it turns out after stop and go traffic my fans go crazy yet my temp needle stays put. then i pop the hood and i see coolant spewing! idk whats going on but i suspect its the thermostat (thanks to cristo for the data)