e39 fuel leak at tank / cold start

[hqstu 780]

Hi All,

I appear to have a fuel leak in my 2002 M54 530:

• Passenger side (left) of fuel tank, coming down the tank surface,  in vicinity of the 3 pipes.
• Appears to occur only on an initial cold start, after a long hot run, then stops?  Nothing on subsequent hot starts or running, nor daily driving around town etc.
• I'd start the car from cold, drive 5 mins or so, hop out and there is a strong raw fuel smell with the fuel tank wet with fuel.  At a guess perhaps 50-100ml or so seems to escape?
• Tops of tank where outlet and return pipes, plus wiring looms on each side are dry, and no visible signs of fuel trying to look around from those top two holes accessed under back seat.
• Fuel tank can be at any level when this occurs.

I am about to replace the charcoal filter up in the left rear wheel well just as a course of preventative maintenance.  Could it be saturated? and some sort of cold start procedure is pushing fuel out a vent outlet which I think is in the vicinity?  No change since changing charcoal canister.

I suspect fuel vapor is condensing perhaps in expansion tank and then getting sucked through perhaps a split pipe somewhere.  No fuel should be getting into charcoal canister as any fuel or condensate should be draining back into tank, unless that particular pipe is blocked?  The vent pipe to engine also has a connection I can't get to without removing it.  I may be able to do that relatively easily (without removing tank)...

Any ideas welcome...  I suspect it's order a swag of new pipes, fuel tank out, and replace everything - since this thing owes me a gabillion $$$ anyway....

Cheers,

Edited May 9, 2019 by hqstu
update...

[hqstu 780]

bump...

[BM WORLD 1282]

have replacement tank and lines if needed . 

[hqstu 780]

34 minutes ago, BM WORLD said:

have replacement tank and lines if needed . 

New lines?

[BM WORLD 1282]

15 hours ago, hqstu said:

New lines?

have new or used tank , used lines etc and probably some new rubber hose etc just call 

Edited May 9, 2019 by BM WORLD

[hqstu 780]

On the weekend I observed fuel running down the fuel supply line only next to the fuel tank just after I started it from cold.  Looking at that pipe from above (through the hole under back seat, that pipe is dry.  There is a connection in between that goes from plastic pipe to rubber hose before connecting onto the steel pipe under the car...

Suspecting it must be that connection, tonight I've bypassed the supply line from the fuel pump on drivers side to the steel pipe underside passengers with 8mm fuel injection rubber hose.  I used a straightened coat hanger to guide the hose across the top front of the tank from hole to hole (under seat) then down and out to meet the steel pipe.  The only other option is to remove the tank...

A simple job in the end, so far so good, all sealed and dry, and time will tell...