New to the forum and e46 ownership - figured it was a good idea to join this community to tap into the knowledge, and what better time than with my first issue!
Situation is - car has begun randomly failing to start - cranks absolutely fine but no fire, in the past if I've left it and tried again some time later it's suddenly started. Started to think it might be the fuel pump/fuse/relay. (also tapped the tank underneath the last time and it started straight after, but could be coincide)
The other day it stalled while driving and wouldn't restart - had it recovered to the garage where it obviously started first time, showed no fault codes and has subsequently run fine ever since BUT.. while driving, if I'm stationary at lights for example, i can intermittently hear a whir/buzz sound, sounds like its coming from the rear and could possibly be a struggling pump (although i may be creating that connection in my head!!)
Checked the fuse under the bonnet, had the relay swapped - noise continues but so far seems fine (although I've kept the tank full above a quarter ever since)
My question is two fold - has anyone experienced anything similar and could share and secondly, if i go ahead and swap the pump out as a guess, does the car have an internal fuel pump accessible via the underneath of the rear seat? I've seen a few things suggesting this is the case on the Coupe, but mine is a convertible and someone suggested i'd have to drop the tank. I'm reasonably handy with a spanner but space/cover is an issue so tank dropping would be far more difficult!!
Car is a 2003 330ci (e46)
Any thoughts/suggestions/advice would be greatly appreciated!!