I went to the dealer a couple of weeks ago for sunroof work and other stuff. Well the dealer apparently upgraded the ECU for a recall. I had no idea this would be happening.
This is the first time the ECU has been touched by the dealer since I got the car in Dec '02. Never had any trouble with the engine.
You know it's coming...
Well yesterday I was waiting in a fast food drive through and I notice that the water temp gauge is spiking and the red light is on! I couldn't have been sitting there idling for more than 5 minutes. I immediately turned off the engine, the fans immediately turned on and I waited for the gauge to come down. Took about 2 minutes. Drove away and everything was fine.
Well today I tried it again. This time on purpose. I let the car idle for a few minutes and I watched as the gauge quickly began to rise. I again killed the engine and waited for the engine to cool down.
Well obviously now I'm freaking out. I'm taking her in to the dealer, but I was wondering if I could get any input from NAM on this. Could the ECU upgrade have caused this or is it just coincidence?

 

it is most likely an unfortunate coincidence. the ECU (or DME) reprogram that the dealer performed is most likely for a recal that has to do with the gas tank leak diagnosis pump.

do you have a regualr cooper or an S. becasue the early Cooper S had problems with the overflow tank (expansion tank) leaking at the seam. there is actually a service bulliten out for this problem. and if yours has leaked out enough coolant it is possible that you are either too low on coolant or have developed an air pocket in the cooling system. either way i'd take it back in and have them check it out.

oh also you did mention that you herd the fans turning on but another issue with mini's is that the power steering fan is on the same fuse as the engine fan. and it is common for the P/S fan to get lockked up and blow the fuse. thus also making the engine fan inop. there has been issues with the engine fans going bad but it is more common for the P/S fan to lock and blow the fuse. but you said that you could hear the fans so i don't think that is your problem here. but i figured it might be some useful information