Cabin fuel smell

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Candycj1
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Cabin fuel smell

Post by Candycj1 »

Hi all

Common thing i know but looking for advice on where to check / in what order. Car's been in the garage for 6 months though visited / accessed regularly for some interior work (retrim & electrics) - been putting off sorting the fuel smell until the interior was back. Seats are now back so now want to get this sorted. The tank has been replaced as have the soft lines to the expansion tank so i'm certain its not from there (no smell in the trunk either, just in the cockpit so i'm guessing its more likely from the front than the back. I see other threads referring to the little perisher - is that my next check?

Thanks
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Hefeweizen
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Re: Cabin fuel smell

Post by Hefeweizen »

Maybe the O-rings at the fuel injectors or the FPR?
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86_6series
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Re: Cabin fuel smell

Post by 86_6series »

I would check the lines going to the exterior pump and filter.
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Candycj1
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Re: Cabin fuel smell

Post by Candycj1 »

Hefeweizen wrote: Sat Jun 22, 2019 2:34 pm Maybe the O-rings at the fuel injectors or the FPR?
Thanks - can’t smell any fuel under the hood nor see anything obvious around the regulator - if it was injectors (or the perisher) should I be able to smell fuel in the engine bay?
Candycj1
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Re: Cabin fuel smell

Post by Candycj1 »

86_6series wrote: Sat Jun 22, 2019 10:20 pm I would check the lines going to the exterior pump and filter.
Thanks will try and take a look - but awkward to get underneath he back where she’s parked at the moment!
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Re: Cabin fuel smell

Post by Hefeweizen »

Candycj1 wrote: Sun Jun 23, 2019 12:08 pm
Hefeweizen wrote: Sat Jun 22, 2019 2:34 pm Maybe the O-rings at the fuel injectors or the FPR?
Thanks - can’t smell any fuel under the hood nor see anything obvious around the regulator - if it was injectors (or the perisher) should I be able to smell fuel in the engine bay?
My leak was so small that you could only smell it when driving. By the time I stopped and checked under the hood the fuel had evaporated. I changed all O-Rings and mine stopped smelling
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Candycj1
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Re: Cabin fuel smell

Post by Candycj1 »

thanks - the car's been in storage since December and hasn't been started since hence i thought there must be a quite visible leak given the strong smell in the cabin without the system being under pressure (other than residual). Even after airing the interior, the smell is back the following day...
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Re: Cabin fuel smell

Post by Hefeweizen »

Candycj1 wrote: Mon Jun 24, 2019 7:58 am thanks - the car's been in storage since December and hasn't been started since hence i thought there must be a quite visible leak given the strong smell in the cabin without the system being under pressure (other than residual). Even after airing the interior, the smell is back the following day...
The heat under the hood amplifies the fuel smell. Unless there is a huge leak it is hard to find out where it comes from.
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Drew
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Re: Cabin fuel smell

Post by Drew »

different car I appreciate, but on my E9 I noted that when I had the windows open I smelled fuel. I eliminated everything engine related by running the fuel pump without the engine on (jumper the relay) and checked for leaks/ smells under the bonnet. With everything cold any leaks won't evaporate so fast. I found and fixed a couple of very minor weeps, but still had the fuel smell

Someone on the E9 forum gave me the idea that opening the window reduces air pressure in the cabin and so draws air from the boot, so likely to be smelling leaks from the seals on the top of the tank

I did note a strong smell of fuel when I lifted carpets in the boot, and traced this to the fuel sender seal. Still haven't fixed it yet though
](*,)
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Re: Cabin fuel smell

Post by Tommys 89 635 »

From what I can remember, there's a small short black rubber hose (~2 inches long) above the intake by the throttle body (close to the firewall) that may have a leak. Even if the gas evaporated you may be able to see a stain on the intake. Hope you find it, good luck
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Candycj1
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Re: Cabin fuel smell

Post by Candycj1 »

Tommys 89 635 wrote: Tue Jun 25, 2019 4:44 pm From what I can remember, there's a small short black rubber hose (~2 inches long) above the intake by the throttle body (close to the firewall) that may have a leak. Even if the gas evaporated you may be able to see a stain on the intake. Hope you find it, good luck
thanks - will do some forensics this weekend!
Candycj1
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Re: Cabin fuel smell

Post by Candycj1 »

Drew wrote: Tue Jun 25, 2019 12:05 pm different car I appreciate, but on my E9 I noted that when I had the windows open I smelled fuel. I eliminated everything engine related by running the fuel pump without the engine on (jumper the relay) and checked for leaks/ smells under the bonnet. With everything cold any leaks won't evaporate so fast. I found and fixed a couple of very minor weeps, but still had the fuel smell

Someone on the E9 forum gave me the idea that opening the window reduces air pressure in the cabin and so draws air from the boot, so likely to be smelling leaks from the seals on the top of the tank

I did note a strong smell of fuel when I lifted carpets in the boot, and traced this to the fuel sender seal. Still haven't fixed it yet though
](*,)
thanks - yes i definitely had issues that end - the tank itself was rusted, the 3 breather pipes from it had holes in, the soft hoses from them were brittle *and* some genius had drilled some holes in the expansion tank - there used to be a really strong smell in the boot as a result. Those have all been sorted now with new main and expansion tank and soft hoses, there's no smell in the boot - though i'm not sure if a new gasket was fitted around the sender, its possible that's a cause so i'll take a look at that too, i guess its possible a small leak could remain with vapours getting sucked into the cabin...
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Re: Cabin fuel smell

Post by jps635 »

Check also:
- The filler cap gasket
- Lines / hoses to the charcoal canister if fitted (up front). There is a long hard line that is fed from the expansion tank that runs under the car.
- The external fuel pump itself. Not that long ago mine started leaking, at fist intermittently, at which point I replaced all hoses. You will know if this is the case as will leave a small dried stain where you park
Put it up in the air or on ramps and have a good poke around underneath with the engine running.
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Candycj1
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Re: Cabin fuel smell

Post by Candycj1 »

Just for information, i've recently swapped out the fuel pressure regulator for a new Bosch replacement as well as a new air flow meter - car is running much smoother now, noticeably less rich than before and the cabin fuel smell is much reduced; might have been the seal on the old fpr causing the strong smell along with general over-fuelling. Injectors are due for an overhaul so will get new seals on them at the same time, hopefully this will remove any last vapours...
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