Hi, I notice a couple of days ago that the coolant was empty but temperature was normal. I filled it to the max mark and a couple of days later it was empty again. I never notice any water or coolant on the ground and temperature never went above normal. Is this a common thing with Minis? I read that a lot of people have problems with the thermostat housing but mine is not leaking at all.

You guys have any idea what's happening with the coolant?

It's a Mini cooper 2006 stick shift

Thanks!

 

Asap check your oil! Be sure that it is not milky in color. If it is it would indicate a blown head gasket.
Steve

 

The reservoir tank may be leaking...since it doesn't hold much the leak may not be noticeable...and it likely doesn't hold enough to cause a significant change in engine temp.

 

^+1

 

+2 on either the coolant tank or thermostat housing. Both are known to fail in the R53.

 

Check the heat shield under the coolant tank.. if leaking you will see the white residue. I haven't had a leaking thermo housing, but it should have signs as well if it is leaking.

phil.

 

Thank you guys for all the input. I'll check when I get home and report back

thanks a lot!

 

If it's leaking you should SMELL it when you open the hood when its hot. It will be a sticky sweet smell.

Definatly check the oil.

 

You may not with either of those leaks. I have had them both and never smelled a thing. I just noticed the white trail of fluid.

 

The tank leak is common on the S (SUPERCHARGED MINI), but not on the plain cooper...
thermostat leak is common....but look around...the car is old enough a hose might be bad, or the radiator leaking/weeping a bit.

 

Ok guys, I got home the the container was again almost empty. I took it to my mechanic and he told me the oil is perfect so it should be a hose or a leak somewhere. I see the white residue underneath the coolant container on that shield but I couldn't find any hole. Im gonna fill it up and try to find where is leaking.

thank you guys for all the input! I really appreciate!

 

Whoops, good catch!

 

Yes, the white residue is a good sign of leakage, you may not be able to find the leak simply because it's in the early stages of leaking and only leaking under pressure, cooling system should be pressure tested.

BTW, good catch, most people would not catch this until it overheated & caused major problems.

 

Looks like your coolant tank is leaking if residue is visible. But check around the thermostat housing as well.

Wish Mini wouldn't be so cheap and add a coolant level sensor in the tank. My 12 yr old VW has such a sensor and it would trigger a warning light when coolant level is low.

 

The center seam on the OEM tank is what leaks, if the level falls below that seam and stays then you know it is just the tank leaking. If the level keeps dropping past that seam or even dropping to empty then most likely its thermostat leak. This was just my experience.

 

Also, do not trust the temp gauge in the car to tell you when you have a problem. They are more like idiot lights then true gauges as the needle will stay in the middle of the gauge until the it is too late and you need to pull over immediately as the needle spikes to full hot.

 

Yeah, That's what I was thinking. The level goes all the way down so it's kind of hard the be a leak on the tank. I'll have my mechanic check the housing to see what's up

thanks guys!

 

True but if he is loosing, what, a cup and a half to two cups of coolant every few days, I would expect to smell it unless he was burning it in the engine. that's a LOT of coolant in a little time.

I hope that's not the case!!! Just odd.

 

I filled up the tank a couple of days ago and I will check once I get home to see how much it lost.

I know it's weird but I really pay attention to these kind of thing and haven't smelled anything.

 

I've had a small leak in my radiator for about 4 1/2 years now. I just top it up occassionally. ('04 S w/90k)

 

Ok I got home and it was half empty. I noticed a little drop of coolant on top of the hose that goes from the tank to radiator (I think) so hopefully is just that hose. Im gonna take it out and check it

 

One note....it might take a few refils to get it topped off if the rad was low....
also if the tank is starting out overfilled (overmax), it might initaly get pushed out the vent before it gets drawn in....
on the s, we have many tank issues, it is preasurizd, but NOT on a plain cooper. On the base cooper, the biggest issue is getting airbubles out.
I suggest you make sure you are putting in a good, mixed coolant, compatible with what you have in the car, and keep it topped off for a few days....then hose the rad, etc off, get stuff clean, and then watch the level over a few days...possible it was just very low, and the consumption rate will stablize to nill, or you might then see a sign of a leak....the thermostat gasket is VERY common, and was revised...it is moleded into the thermostat. Cars with molded silcone hoses, rather than black rubber also tend to use a bit of coolant...the hoses are a bit more permimable.

 

Thanks man. Ive been thinking and there's a lot of thing that could be causing this. I think Im gonna have my mechanic just take a look and fix it for me. Last thing I need right now it's something bad on my car while I wait to find the problem.

 

Guys, Im 100% sure that the problem is the hose from the coolant tank to the radiator. Where can I buy that hose? I checked on autozone and they don't have it and an online place was asking for like $70 bucks for that little hose. Do you have any recommendation?

Please let me know

thanks!

 

There is no hose from the coolant tank to the radiator. It goes from the coolant tank
to the thermostat housing, number 4 on this diagram. The diagram says about $22, but
realoem.com's prices are sometimes out of date. Checking at pelicanparts.com says $32.25.
Check the diagrams on realoem to confirm which hose you really need.
http://www.realoem.com/bmw/showparts...19&hg=17&fg=05
If you meant a 2006 MINI Cooper S instead of a 2006 MINI Cooper, then it's number 4
on this diagram ($28.50 at pelican).
http://www.realoem.com/bmw/showparts...36&hg=17&fg=05