1st Gen R53 Cooper S Overheating problem?

:cornut:I'm very glad to hear that. Maybe you could pass that along to JD Powers/Dependability Study.:lol::lol:

Jasonopcorn:opcorn:

 

Does this look familiar?
This is after a stressful day at the track in terms of engine load and rpm, but temps never rose above 200F.




I guess I could be lucky and just have a bad cap, or more seriously I could have a head gasket issue that is manifested only under high rpm and max boost conditions. My compression is not bad either, certainly not Wednesday build strong numbers of 180, but still a decent 160ish across the board.

 

Just about always have a bit of that after the track... Even thought about a metal expansion tank.

 

How would a metal tank help? It is all spewing out from under the cap. My tank is leak free and can hold pressure.

So, unless I have a faulty cap, I am likely forcing combustion gases into the coolant via a minor head gasket failure.

 

Metal because I've heard of the plastic one failing at the track and maybe get a better seal at the cap. Mine has spewed a little out from first time at track with it, not as bad as yours but nothing can be found wrong with it. Have you checked to make sure there are no cracks in the tank itself??

Also after flushing the cooling system and filling with 50/50 coolant and a water wetter the problem was reduced, not gone, but reduced along with a bit lower water temps...

 

That happened to me at T-Hill, I nearly panicked as steam started boiling out from under the bonnet. This issue was an overfilled tank. Overflow should be kept just to where you can see the fins in the bottom (or the minimum line).

 

My tank is certainly showing signs of age as noticed by the color, but it is not leaking.

Regardless, I am going to replace it and the cap. I mean it is 5yrs+ old now, and I would HATE to be that guy that spews slippery coolant on the track If my original tank were to suddenly fail. Better safe than sorry.

 

Good point, leave room for expansion and check after each session, adding a little water if needed.

I have never left the track after a session and not had some stuff on top of the tank.... A quality expansion tank has been on my list for awhile.....but something else always seems to get bumped up in front of it....

 

My coolant tank looked exactly like that after my most recent track weekend. I cleaned the expansion tank after every run, and it showed up every time. Oil temps were up around 270; I don't have a water temp gauge, but the idiot light gauge was normal. I drained and filled the cooling system last fall around 95,000 miles, too.

 

:cornut: I've had Margi back now~2wks and she runs like her old self even on spirited Texas back country roads.But the strangest thing has happened. Her normal operating temp used to be 215-220(as per CHKMINI above) and now it has dropped to 200-205,go figure. Mind you I'm not complaining, just some what puzzled. Not wanting to 'look a gift horse in the mouth',I accept her as she is and just 'drive on soldier.'ut:

Jasonopcorn:

 

For my 1st Gen '06 JCW car street coolant temp is 194F, track temp is 200F, and very consistent.

 

To all that have had an MCS overheat:

It has happened to me twice and both times it was the cooling fan. I live in Florida and my '03 MCS doesn't like to sit still. My mechanic explained that the MCS just leaves no place for the hot air the fan blows to go when the car sits. It reflects off the hot engine block and the electronic controls on the fan bracket literally melt. When the car is moving, air off the fan at least gets a path under the engine. This situation is made much worse with the A/C running.

So, basically it's a design "feature" and now my driving style includes lowering the windows and opening the roof when sitting in a traffic jam. If you doubt this theory, open the bonnet and look at how little room there is behind the stacked coolers and visualize how all that heat has no where to go when the car is stopped.

In conclusion, if you experience overheating, check to see if your cooling fan is running. If not, it's broken and it's a pricey (~$400) fix. The fan comes as an assembly and nothing is easy to get to on a Mini.

 

A resistor for the radiator fan can fail, it's been known to happen even in the winter. Another issue, on early models the power steering fan and the radiator fan shared the same circuit, if the power steering fan seized it could blow the fuse serving both fans (a TSB was issued for this problem), but a fan bracket melting sounds like something was lost in the service explanation. Nothing on the radiator will melt due to convective heat from the engine.