Humming/droning noise on start up

[Jamturbo]

Hi,

I am experiencing a humming/droning noise on start up which feels as if it is coming from the back, it vibrates through the car. It lasts for about about 10-15 seconds and then stops. Car drives as normal.
The noise doesn't always happen.

It is on a 2004 3.0i e85.

Any ideas what this might be?

Thanks

 

[Conrod]

It's the fuel pump (situated in the tank).

 

[Jamturbo]

Thanks Conrod. Do you think it is anything to do with a full tank and e10 fuel. Just wondering if that is upsetting the pump.

 

[BumpyZ4]

Does it do it on just cold or hot starts? Or both?

 

[Roberltd2]

Mine does it after filling up with petrol but only when idling. Gets less noticable as the tank empties. Not there at all once the tank gets down to half full.

 

[Roberltd2]

Forgot to mention that it's no worse now than it was over five years ago when I bought the car

 

[Jamturbo]

Thanks for replies. It happens from cold. Once the car is warmed up I don't think I notice it. I rarely fill up the tank to full but the paranoia caused by the recent fuel crisis down South has seen a fuller tank. I shall use it down and monitor.

 

[Ewazix]

Fuel pump.... Mine did it after it was sorned over winter, I was advised to stick some protective fuel additive in the tank and it cured it. I've used a bottle of Wynns Formula Gold Petrol treatment once a year before laying up for winter and not a had a problem since.

https://www.halfords.com/motoring/engine-oils-and-fluids/fuel-and-oil-additives/wynns-formula-gold-petrol-treatment-500ml-166754.html

 

[Liam22]

Probably the charcoal canister. More noticeable on colder days.

 

[Ewazix]

Probably the charcoal canister. More noticeable on colder days.

I didn't realise UK cars had the US required EVAP emissions kit with carbon canisters on the tank? :?
...... But having said that I just assumed the OP was UK based

 

[Liam22]

I didn't realise UK cars had the US required EVAP emissions kit with carbon canisters on the tank? :?

This part https://www.realoem.com/bmw/enUS/showparts?id=BT53-USA-06-2004-E85-BMW-Z4_30i&diagId=16_0539

 

[Ewazix]

I didn't realise UK cars had the US required EVAP emissions kit with carbon canisters on the tank? :?

This part https://www.realoem.com/bmw/enUS/showparts?id=BT53-USA-06-2004-E85-BMW-Z4_30i&diagId=16_0539

I'm still not sure UK RHD cars have the canister, if you follow the link you posted to the canister part number it lists the applicable models which are the US versions. By going back in RealOEM and looking at the listings for RHD Euro market cars, it looks like the EVAP canister is listed as an option for use with leaded fuel. It's confusing and I'm happy to be wrong
https://www.realoem.com/bmw/enUS/partxref?id=BT53-USA-06-2004-E85-BMW-Z4_30i&mg=16&sg=10&diagId=16_0539&q=16137839840&series=E85

 

[Jamturbo]

Thanks for your input.
Since using up the the fuel , I noticed that the noise has stopped from 3/4 full to just below half tank. I shall try the treatment as others have suggested as the weather is starting to turn.

 

[Liam22]

I'm still not sure UK RHD cars have the canister

Admittedly, mine is a later E86, but definitely fitted as I removed it and it's sitting in my workshop 8)

 

[enuff_zed]

Thanks for your input.
Since using up the the fuel , I noticed that the noise has stopped from 3/4 full to just below half tank. I shall try the treatment as others have suggested as the weather is starting to turn.

So if you've never really brimmed the tank, and now noticed this noise, it is possible that all you've done is changed the resonant frequency within the tank by reducing the air gap and now the noise is audible. That would be borne out by the fact it disappeared as the level dropped.
Only way to confirm is to fill it to the rim again I suppose?

 

[Ewazix]

I'm still not sure UK RHD cars have the canister

Admittedly, mine is a later E86, but definitely fitted as I removed it and it's sitting in my workshop 8)

Can't argue with that :lol:

Cheers I've learn something new