Hello All,
This is my first time on this site and I am glad to find you! I am having problems with overheating in my '03 Mini Cooper (NOT "S"). First, at times I hear a rushing water sound under the dash when I rev the engine. Stuck thermostat? Air in the system? Where is the radiator bleed valve?

Second, at times when sitting in traffic my temp guage is pegged, then after turning on the heat full blast and revving the engine it goes back to normal. I took it to the dealer, they diagnosed the low speed fan isn't working and to replace is $680. My fuse isn't blown. I hear the fan kick on when I turn off and park the car. Any thoughts on this diagnosis?

Your thoughts are appreciated!
Bill

 

Had this same thing happen to me after my JCW install - lots of air caugth in the system. I just wrote a PM to mbcoops about this. Partially unscrew the bleeder valve - upper hose left of center - in the coolant line. Its a plastic thingy with an X on for a screw driver. Then, remove the overflow cap. Let the engine run until the coolant expands enough to push all the air out. If outside temps are cool, the coolant may not expand enough.

As air is removed from the system, the coolant level in the overflow will drop. Keep an eye on the level...if it drops too far, more air will get sucked into the system. Keep adding fluid until there is no more coming from the bleeder valve, and, the level in the overflow tank is steady at the 'HOT' level. Turn the heater on high heat and low fan...I think low fan.

This cured my problem.

 

There is also a secondary bleeder screw, number 2 in this pic...



I'm not sure if i'm catching what you're saying. Are you bleeding the system with the cap off?
The pressure that builds up with the cap on helps to purge the air.

 

Thanks for the replies. With the cap closed and the car running and warmed up I bled some air off the bleeder valve at the top left of the radiator - a little bit of air then it squirts the coolant. Still have the rushing water sound. Does this have anything to do with the thermostat or do you think my overheating is caused by the air in the system - air bound? How accessible is the secondary bleeder valve (#2 in pic)?

Also, where is the low speed fan? Are there two fans - low speed and high speed? This is what the mini dealer is diagnosing, but they ignore the rushing water sound. I'd like to solve this rushing water sound before I spend $680 for a low speed fan they say is to blame.

Thanks for your help.
Bill

 

the second bleeder is on the back of the engine near the battery. is on the lines that go into the car for the heater. if you look to the right of your ps reservoir and down you will see it.

there are 2 speeds for the cooling fan, they work separate meaning one can run with the other being damaged. if you took it in and they told you is the fan, i'm pretty sure is the fan. we can test run the fan with the diagnostic tools and if it doesn't run then theres the problem.

 

When bleeding it is necessary to remove the overflow tank cap - according to Bentley. A poor analogy, but I guess this is sort of like sucking water from a straw and placing your thumb over the top end...no water falls from the straw. Remove your thumb - cap - and things move.

 

yeah you got it.

 

But if I open the bleeder I'm opening the closed system and therefore the air in the system has somewhere to go. I don't/shouldn't need to remove the overflow cap.

 

Sorry, I posted a pic for the MCS, here's the one for a MC, still number 2...

 

Think of the straw analogy...the straw is open at the bottom. A mechanic actually did this to my car when hot; opened the bleeder first, while the engine was running, and then removed the overlow cap. Air, then fluid came out of the bleeder and the level in the overflow dropped.

I did back way off when he did this, which he found funny. But, you don't usually get to just brush off coolant burns And as of late, its harder and harder to maintain my girlish figure

 

Yeah but the fluid is being circulated thru the system and when there is a leak in the system, with the cap on, it draws fluid from the overflow to compensate so the bleeder valve should function in a similar fashion. As air is removed fluid takes its place.. This is unlike the straw analogy which is a closed system. I'm sure opening the cap makes sense on some level but for me it seems like you would run the risk of emptying the overflow and re-introducing air.

 

Maybe my car (or me) is just weird, I can only run it for so long with the cap off before the coolant starts to come out of the tank.

 

I appreciate all the info. Here in the Philly area we are experiencing the second coming of winter. When the weather warms up I suppose I'll be able to bleed alot quicker/easier. Thanks again for the help.