Help! At a loss to explain loss of water...

["Tom Borden" <teborden2@xxxxxxxxxxx>]

Was bombing down the expressway en route to work and check engine light kicked
off two miles shy of exit.  Drove to exit and stopped at light down end of
ramp.  Notice steam/smoke wisps coming from under hood.  Drove four blocks to
usual commuter parking lot, but noticed engine starting to "clack" a little.

There were no apparent hose diconnects or breaks, but I lost all of my water
(well, reservoir was bone dry).  Tuesday after Labor Day a mechanic will look
into it, but am curious... any thoughts on whether this is water pump failure?
Could it be that without water circulating, it all overheated and forced its
way out of every engine/coolant system seam?

Could it be a thermostat issue?

Lastly, the oil seemed to be fine, but I wonder about that clacking.  How long
can you drive with guage on hot before you do damage, and what is the sequence
of things that go first?

The BMW board rules!  Thanks for any light you can shed.

Tom Borden

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