2008 - BMW 730d - cold starting

[TooLateForAName]

Other option could be battery.

Is it still on its original battery? I know they should last longer than 5 years, but if everything else is good...

[heners54]

TooLateForAName said:

Other option could be battery.

Is it still on its original battery? I know they should last longer than 5 years, but if everything else is good...

Agreed this is a possibilty. I've just replaced a 5 year old battery that died, they don't like the cold or living outside on some cars.

[lescombes]

Don't be tight.... change the glow plugs... they don't last forever, plus some vehicles keep reheating them until engine get up to a certain temperature (emissions crap), which will reduce life. Use a decent quality one...after all these years I tend to fit NGK's or Genesis brand...
If you still have issues after the glowies have been changed it could be the relay/module, but whatever....you need to change to glowies to save duffing in a new relay/module

[Toaster Pilot]

Glow plugs don't even cost that much although I'm not sure how easy a DIY job they'd be on a 730D due to access etc.

Changed the 3 out of 4 I could easily access on my Felicia and the difference in cold starting was immediate.