My 525i had been sitting outside for about 2 days with temperatures gradually decreasing until tonight when it reached -7 and I hopped in the car to head home. Apart from feeling quite stiff, everything worked fine except for the speedo and RPM gauges. The RPM said I was idling(just after cold start mind you) at about 300rpm, while the speedo never rose above 10 once I started driving. When they moved, they did so very sluggishly. Eventually, while on the freeway at somewhere around 70, the RPM needle showed 1000rpm and the speedo registered -5mph.

I estimated 70mph based by setting the MAX SPEED alarm to 70 and accelerating till it chimed. I surmised that the MAX SPEED indicator was actuallyy accurate by testing different speeds alarms and observing my speed in relation to the traffic around me. I compared both observations to my knowledge of how people generally drive on that stretch. I also based my speed on the seat-of-my-pants feel and my visual perception of velocity.

So, why would the MAX SPEED alarm work, but the RPM and speed gauges not? And, all the above considered, what is broken? All other gauges and indicators seem to work properly. The archives didn't seem to have much info related to this particular malfunction.

Would appreciate your thoughts guys.
Thanks,
Ben