2005 BMW E61 starting issues

[Wilmslowboy]

My BMW has twice in the last 2 weeks, struggled to start, my limited automotive logic points to either a dodgy start button, clutch switch or earth strap ? Anyone shed any more light on the problem ?

Symptoms (when it fails, which is only very very occasionally)
Insert key (a black plastic fob); dash lights up
Press clutch, press start button, and nothing, no cranking, no start clicking, no attempt to start.
Then try it multiple times (on one occasion, it took 20 minutes) then suddenly its starts as normal, not laboured, just the usual quick ¼-second crank and fire right up.

Noticed something odd: when it does start after a failed attempt, the clock has reset , as if the battery had been disconnected and reconnected. I'm not sure if this reset occurred before start attempting or on starting.



2005 E61 Touring, Manual, Petrol

[paul_c123]

Could be 100 things but one of them is, the battery terminal is loose.

[Wilmslowboy]

paul_c123 said:

Could be 100 things but one of them is, the battery terminal is loose.

I thought the same, checked it (battery in the boot), all tight as should be.

[njw1]

There was a recall for the battery positive cable, could be that if it hasn't been done already?

[E-bmw]

Wilmslowboy said:

paul_c123 said:

Could be 100 things but one of them is, the battery terminal is loose.

I thought the same, checked it (battery in the boot), all tight as should be.

What about starter leads, battery earth strap, engine earth strap, all could do the same, check all ends of each.