Originally Posted by wpoll

Just been reading back over this thread and I don't see any info. on the ignition switch ring antenna, which could casue your issues if it failed.

But more importantly, I recall you mentioned the key went through the washing machine... and you only have the one key. A corroding circuit in the key will certainly lead to a no-start scenrio.

The diamond key used by BMW isn't like many other keys in that the EWS transponder circuit is on the PCB inside the key. While it's doesn't use the battery, it is fragile compared to the ID13 and ID 48 transpoder chip used by VW etc.

BMW key..



Older VW ID13/48 chip...



It might be prudent to confirm the correct operation of the EWS system (key, ring antenna etc.) at this point, espeically given the symptoms and the history... (key gets washed, then becomes intermittant a few weeks later, then fails completely).