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Gas leak?

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cornwallis
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Gas leak?

Post by cornwallis » Fri Oct 22, 2021 9:42 pm

After filling up my car and driving 5 miles in city traffic, I noticed a heavy gasoline smell. I noticed the outside of the tank was wet. I don’t think the tank itself has a leak but not sure what’s causing this. Appreciate any input.
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Hector :twisted:
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hornhospital
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Re: Gas leak?

Post by hornhospital » Sat Oct 23, 2021 2:42 am

Probably a filler neck hose is cracked. Did you run it full as you could get it?
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cornwallis
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Re: Gas leak?

Post by cornwallis » Sat Oct 23, 2021 8:55 am

I filled it up full - and probably one or two more squeezes from the nozzle. I do that every time.

I imagine the gas would slosh around and wet the fill nozzle as a make turns and drive.

Is it possible to inspect the fill nozzle to look for cracks?

Is it part of the tank or a separate part?

If separate part how difficult is it to replace?
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sharkfan
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Re: Gas leak?

Post by sharkfan » Sat Oct 23, 2021 10:57 am

Gently ease that rubber surround up and off the filler neck. I say gently as if you are too rough you will crack the filler neck. Once it is off you will see the top of the tank, the filler neck to the tank and the breather connections - it'll be obvious where the leak is.

Edit to add; while the rubber pad is off, clean it and treat it - it will probably be pretty hard but should clean up ok.
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cornwallis
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Re: Gas leak?

Post by cornwallis » Wed Oct 27, 2021 11:08 am

Hi sharkfan, thanks for the advice. Busy week but I’ll check this out during the weekend. From the schematic below, looks to be one of the rubber seals (#2 or #3) could be bad. I’ll check in later. I hope it’s not weld/joint between the filler neck and tank.
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GRNSHRK
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Re: Gas leak?

Post by GRNSHRK » Wed Oct 27, 2021 4:54 pm

Hector, number 3 is "possible" (gas cap gasket) but I would be taking a closer look at the 3X vent tubes adjacent to the filler neck, which I would also check, for corrosion, etc. :-?

You will be able to see a lot more once you carefully remove item number 2 [-o<
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cornwallis
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Re: Gas leak?

Post by cornwallis » Thu Oct 28, 2021 1:34 am

Thanks Bobbo, I’ll check that out too. Hope it’s not the vent tubes. [-o< [-o< [-o<
Hector :twisted:
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cornwallis
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Re: Gas leak?

Post by cornwallis » Sun Oct 31, 2021 6:48 pm

After removing the rubber cover (#2 above) degreasing and cleaning the area where it connects to the tank, I didn’t see any obvious issues: no corrosion at the vents tubes \:D/. I did tighten the hose clamps on the vent hoses and the gas cap gasket likely needs replacement. Hope this fixes it.

Question — the vent hoses are braided and look frayed— possible this is where gas was seeping. Where do these lines end up? Considering replacing these. Thanks!
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Re: Gas leak?

Post by GRNSHRK » Sun Oct 31, 2021 7:37 pm

They go to a sort of "vapor reservoir" in the trunk, behind the right hand side inner panel :-"

They don't appear to be in bad condition, however :-k

I would at least tighten the clamps, for starters, and I would not top off when filling up either :-?
:mrgreen:
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86_6series
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Re: Gas leak?

Post by 86_6series » Mon Nov 01, 2021 11:12 am

Look like the gas cap gasket will solve your problem.
The wet fuel is running down the 3 hoses thru the
grommets from the gas cap cavity area and spilling
onto the gas tank cover.

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Steve M6
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Re: Gas leak?

Post by Steve M6 » Mon Nov 01, 2021 8:18 pm

Those fabric covered hoses that BMW used WILL fail. I have replaced the fuel lines in both my 6ers and my BMW motorcycles produced during the same era because they will seep gas. They will appear to be "wet".

This is a very common problem, and I have even encountered some who have sold their cars because of the fuel smell they could not find. Usually filling the tank makes this problem worse.

Replace one line at a time, and use new worm drive clamps. If memory serves, there are four separate fuel lines to renew between the filler neck and expansion tank under the rear parcel shelf.
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