BMW Repair: Drove 1994 740il Through Deep Water...., crankshaft position sensor, level sensor

Question
Not that I wanted to but it is November in Seattle.  Sometimes it just happens....Anyway, car died in the middle, tried to start with car standing in about a foot of water....Got out tow strap & nice person pulled out into parking lot where car will not turn over.  Clicks like bad starter.  

Tried to jump, same response, but battery gets weaker with each attempt.  I do have soaked air filter, but pulled plugs with no visible sign of water in cylinder (evaporated I imagine).  All plugs look good & clean.

I JUST got the car & don't have a repair manual, am freaked out that I have seized the engine, and it is late on a Saturday night so no where else to turn.  Any assistance would be greatly appreciated~Ben.

Answer
Hello Ben,
I am sorry to hear about your predicament. And I am sorrier that there is no quick fix to this problem.
The car stalled in deep water due to a short that was caused by the water. It can be a short in any of a lot of things.
But did the starter still crank the engine immediately after it stalled or did it just click after stalling?
The best solution is to have it towed in the morning to a
repair shop. With the key turned off, have the  battery removed and recharged. Then ask the mechanic to blow air into the starter and alternator. Disconnect cable connectors to the camshaft speed sensor in front of the engine and blow air into it too(better still let them spray electronic contact cleaner into the pins and sockets of the connector before re-attaching).
Do the same specially to the crankshaft position sensor located on the left side/or right side of the engine block.
Make sure that the oil level sensor at the bottom of the crankcase gets the same treatment. This sensor usually affects the EWS(anti-theft circuit) and could prevent the engine from starting. In some cases, disconnecting the cable connector to the oil level sensor can correct a no crank/no start condition. Remove the top and side engine covers and blow air on all electrical cable connectors(no need to disconnect not unless it is obvious that the area had been drenched). Also remove the E-Box (electronic box)cover at the right side firewall and see if moisture got in. If yes,
detach various connectors to the DME/engine control module,
spray with air then electronic cleaner, dry out and re-attach. Re-install charged battery making sure key is in off position.
These pretty much covers everything. If it still does not crank try jumping the starter to verify if the starter is really the problem. If it cranks but does not start, then
check the  engine ignition fuses (5 in a plastic box)also
found in the E-box. If it still does not start, then bring it to a dealer for  further diagnosis.