[mr_mason]

morning all.

my 318i is developing a bit of an issue just in time for the cold winter.

under partial load in the low gears it makes a pulsating almost metallic growl. under a wide throttle the noise goes away, it doesnt cause any fluctuation of the revs and doesnt effect drive at all.... noise is defenitely coming from the right hand side (as looking under the bonnet) of the engine, almost air intake / maf / throttle body area. its also more noticable from the passengers seat when inside the car which backs up the notion of it coming from that side of the engine. ive tried to get a video of it but its proving difficult.

to add to this its been having a bit of difficulty starting recently. occasionally it chugs a bit while trying to start, and this morning took 3 attempts to fire... turns over fine but wouldnt fire. when it did start there was a noticable petrol smell when stood outside the vehicle.. i didnt notice any residue from the exhaust but the ground was already wet.

when its warm it runs absolutely fine... starts and drives totally normally, MPG has stayed constant.

please bear with me as this is my first BMW so i dont know these engines at all.

the first problem i would have put down to an air intake / maf issue. while the second problem i would have put down to possibly coil pack / plugs.

it was serviced a few months ago and while the issues are getting worse over time, the service didnt make any real difference.

opinion on where to start?