Tank odours

[gs.davies]

My garage stinks of fuel. Tank is an early 60’s type, no leaks, but currently has a vented cap and the open pipe breather.

Is there anything I can do to reduce the stench?

I’ll swap the cap out for a non-vented type, but is there some kind of filter I can fit to end of the breather?

[NZmember]

Mine stinks when the tank is full. So I don't fill it to the brim.

[Peter Laidler]

Yep, as did mine Gary. Your comment should be a lesson for everyone.

I couldn't understand where the smell was coming from. Nothing obvious in spite of carefully examining all the hoses and joints. I even pressurised one of the tanks (not a great success but it worked - after a fashion) to load up the fuel system. But couldn't find anything.

But coming home from a short trip, a tank-to-pump hose gave way. I limped home and replaced the hose. Only then did I see that the hose and a few more, werre slowly rotting from the INSIDE.

The petrol smell was emanating through the thin rotting non-ethanol compliant rubber. So I set about changing them all and haven't looked back. And now I have a small zip-lock bag in the spare wheel well hat contains a few lengths of hose, a couple of stoppers and squeeze clips.

Change your hoses for ethanol compliant today - or certainly before your next trip

[gs.davies]

Thanks Peter, all the hoses are Ethanol compliant Fuel Injection spec R9 (except for one short section which is R6 leading from main fuel pipe under the bonnet to the inline fuel filter), and all other seals and gaskets through the system are now also ethanol safe.

I think it's where it's garaged most of the time, usually left with mostly a full tank, but I just don't recall it being that 'fumey' back in the day. Does make me wonder if the fumes built up enough if there's a spark ignition risk, and while I doubt there is, it is annoying and is the cause of complaint from SWMBO. Maybe modern petrol smells worse than the stuff from back in the day?

[Peter Laidler]

Strange that.... I'd replace them anyway. But that's just me! Vapour (that's what a smell is don't forget...) doesn't just come from nowhere as you know if you live near a farm. And petrol vapour in a garage is a good clue I say. Been there, done it.........

There's an irony here too because last weekend coming back from the coast in my little red RCSport, I saw a broken down mini traveller on the A34. So stopped and reversed back to see if I could do anything. But he already had help on its way. Yep........ split fuel hose!

I'll shout my tits off again and again to all forumers ......... change to ethanol resistant hoses

[Polarsilver]

Agree with Peter Re- the fuel hoses .. however i found the so called ethanol compliant fuel hoses can get very hard in their form after a few years & will start to crack.. another service item to check & maybe need to replace the so called compliant Fuel Hoses.

Found a ( Pace Fuels ) 4 Star Petrol Supplier in Central Buckingham ( shame its not 5Star) so will be filling up there in the future .. they even have a proper Pump Attendant in a Brown Coat ..yes a good old boy who you can talk to while he is filling your Tanks.. go to pay in the shop where they sell "Black Jacks & Fruit Salad Chews".. great stuff.

PS also check the Fuel Tank Sender for weep.

[1071 S]

The original poster claims no leaks but..... I would looking very carefully under the tank in the boot and under the car. Pounds to peanuts fuel is leaking out and evaporating before leaving too much evidence.

It's VERY unlikely that a vented cap or breather are releasing enough (if any) fumes to stink up the garage.

I had a similar bad smell and eventually tracked it to (old) leak in the cross tank fuel line of my S. Fuel had run into the gully between the boot floor and the rear firewall, then soaked through the firewall to floor pan join and into the rear seat base foam. Had to replace the old foam base to get rid of the smell.

Another possibility is that the fuel cap is leaking as you corner (with a fullish tank) and running down between the rubber seal and the tank neck and collecting (before evaporating) inside the boot behind the tank...

Reminds me of a spot of excitement a few years ago. Just standing around fuelling a mate's completely original TR8 (30+ years old but only 30K miles) when people starting running around and shouting.... Looked down to see a spreading stain on the concrete forecourt.

Having a look underneath after carefully pushing the car well away from the pumps we could see fuel trickling out of an original but very rotten fuel line....

Cheers, Ian

[whistler]

I fitted new locking caps to my 66SDL. Notice same smell in garage so checked and I'd fitted vented caps but should have been closed ones as the tank has a top breather pipe. Change caps, no smell.

[Peter Laidler]

Sorry to slightly disagree re tank caps but I don't believe that petrol vapour leakage has anything to do with the tank cap either. Petrol fumes ALWAYS descend and the tank cap is above the level of the fuel by design. Unlike helium which is lighter than air...., Just ask the fire brigade. That's why you should always have a fire extinguisher in a pit

[gs.davies]

Well, I've been over it again, no signs of any leakage apart from where there's fuel stains on the rear from where the fuel sloshed out of the tank when full through the vent or through a previously ill fitting cap. The tank hadn't seated quite right and coupled with a modern too large neck seal, prevented the cap from sealing properly. The cap now seals well an is not impeded from doing so, the seal in question being one of Fred's Viton items and is in perfect condition. There's no smell inside the boot, that just smells of the spare tyre, so the smell is definitely outside.

I did notice that the breather pipe at the top of the tank was taking a route straight out and down, and there's actually a tab on the underside of the parcel shelf, directly above, so I've routed the breather upward before it descends down the rear edge of the tank and out the boot floor. Not sure if that detail is significant or not.

Peter, I take your point about the fumes being heavier than air and so they'd fall, but I'm sure you'd smell an open jerry can of fuel if left in the garage despite the direction of the fumes.

As per Whistler's experience, I'll try an unvented cap and see if that helps at all. Thinking about it, when the car was last on the road in the mid 90's it had an original type locking cap with a red part underneath. Having been looking at caps, I've noticed that unvented ones have a red segment opposed to green on the vented ones. This little red part was eventually removed from the varnish in the bottom of the tank last year after it had to be broken off when the car was stripped for restoration on account of the key being missing, so I suspect my recollection of it not ponging the place up might have something to do with the cap.

Still, is there something that could/should be fitted to the end of the breather pipe, or is that really best left open to allow vapour out?

[whistler]

Sorry to slightly disagree re tank caps but I don't believe that petrol vapour leakage has anything to do with the tank cap either. Petrol fumes ALWAYS descend and the tank cap is above the level of the fuel by design. Just ask the fire brigade. That's why you should always have a fire extinguisher in a pit

I agree about vapour heading for ground but like electricity it will often find the path of least resistance so after a drive the tank will be slightly pressurized and a vented cap is often the easiest for the tank to vent vapour pressure before heading for the ground.

I agree about the fire extinguisher for a pit.

[1071 S]

I would suggest the vent is to allow air in ...not fumes out. If the tank is sealed a vacuum will develop as fuel is used. This can't be good for fuel pressure..

Cheers, Ian

[Catmint]

You can get little one way valves for tank breathers (used in motorsport) some where like demon tweeks

[Rolandino]

Ive put an in-line switch to the fuel pump. When coming home I switch the pump off and let the engine run till the fuel bowls are empty. I then have a length of windscreen washer hose that I put on the end of the breather pipes whic run to the underside by the rear subframe (I use a small section of fuel hose to mate the two ends. I then put the ends of the washer pipes under the garage door and out to the world. One other plus point, you dont get cats of foxes anywhere near the garage, they hate the smell of petrol. Try it, works 100% perfectly

[swifty]

Strange this as I have 3 twin tank cars in the garage at the moment and not a smell of petrol at all …. Shirley

[Rolandino]

@swifty

I dare you to walk in your garage and use the gas lighter spark !

You just cant smell it or you have good ventilation in your garage !

|Just like women, some smell, some dont !

[swifty]

Use a gas lighter . I’m welding in the garage and using a space heater in the winter . It might possibly be the size of the garage that counts . So bigger garage more ventilation ? … My garage is 70 ft X 15ft inside . … Shirley

[Allen Brzeczek]

It seems as though I might be a bit of an odd ball here as I quite like the smells associated with older vehicles. When I enter my garage I find that the smell welcomes you in and is part of the character of the car, mind you I believe that "proper" petrol smelt better. Just to elucidate my liking I am a seasoned two stroke fan, at least one of my motor bikes shares the garage with my S at any time - much to my wife's chagrin and neighbours amusement I very often exit my garage surrounded by a cloud of smoke.