Random cut outs e39 m5

[TheAngryDog]

Coming to a stop and it cut out and started again itself. It's like the ignition cut as my doors unlocked. Could this be a faulty ignition switch?

[Cemesis]

Is it consistent or only when hot/cold? Any fault codes?

Could be fuel filter, a coil, bad fuel, electrical (alternator) or an air leak

[TheAngryDog]

the ignition went off. I don't think it's a coil etc.

[rfsteel]

I've a similar issue with my M5, though mine is after turning the key, the starter does not engage, or even click to indicate a flat battery. I usually have wiggle the key and multiple turns to get the engine running.

Here is a link to a how to on rebuilding the ignition switch;

https://www.bimmerforums.com/forum/showthread.php?...

[Gemmot]

Could be something as simple as a loose earth or negative wire in the engine bay. Worth having a poke around

[rassi]

On a C43 I had a long time ago, it was the cam position sensor that had to be replaced after similar behaviour. But in reality you need to have a diagnostic done and any codes read. Difficult with intermittent problems, I know.

[TheAngryDog]

It is definitely something electrical, although it hasn't happened since and the car has been getting a lot of use. Hmmmm.

[e21Mark]

Cars are always going to be better for getting regular use. Could it be moisture causing a short or a sticky relay maybe?

[TheAngryDog]

e21Mark said:

Cars are always going to be better for getting regular use. Could it be moisture causing a short or a sticky relay maybe?

Ive used it every day for the last few weeks with the exception of Friday last week. The cars days are numbered in my ownership.

[Seesure]

Personally I've had similar with both my E39s, usually when still rolling but when very slow and the steering goes heavy and the brake pedal gets hard. I've not had either car restart unless I've still had enough speed to release the clutch and get a "bump" start.

I never had any codes and it was totally random, other owners on the US forum also mentioned similar symptoms /occasions.

The one thing that occurred to me was that I was usually coming to a junction to turn so I suspect the power steering pulled the revs down to a stalling point.

The issue was it was never constant but just happened.... Over the years I had all the CPS, O2 and Mafs replaced on the first car and it still occurred occasionally ....