petrol fumes in cabin

[lombardi]

Hi everyone,

Iam getting a lot of petrol smell in my cabin of my 105 1750 veloce 1968,to a point where i am getting headaches,i dont believe its a fuel leak,as its very frugal on petrol,could it be a vacuum effcet from window open,or an issue with carbs,although i did get them serviced recently.your opinions would be greatly appreciated. garzie angelo

[alfagtv100 (Biggus)]

Hi,

Some things I tried on my 1750.
- Boot lid seal
- Filler cap seal
- Rubber hoses (from fuel tank, to fuel filter, to fuel pump, to carbies)

On mine, replacing the boot lid fixed the problem.

Cheers,

Marco.

[AndrewO]

Hi,

I've got a '68 as well.  I had the same problem and went through the same things as Marco but it kept on happening (although I think the boot seal, and filling rust holes, did fix some exhaust fume problems).

I found the o-rings under the pump jets on both webers were perished.  They looked fine but when I took out the screw they were in about 15 pieces each.  The tell-tale (I should have noticed before) was a stain on the side of the carbs.  The petrol flows down and pools in a little well on the side and it stains a kind of red colour.

You'll never notice the difference in consumption.  If it is raw fuel (not exhaust gas) then for mine it was maybe half a teaspoon over a day but in a hot engine bay the fumes are very strong.

Check all the hoses to the carbs as well, the ends might be brittle and even a tiny crack can leak under pressure and you'll smell it before you see it.

Good luck.

[lombardi]

THANKS FOR YOUR VERY INSIGHTFUL REPLYS,WILL TRY.REGARDS ANGELO

[pep105]

Hey Lombardi

Andrew and Marco are spot on

My GT Junior has a damaged boot lid and it doesnt seal. As im in the process of driving around getting quotes to respray the car, ive taped up the boot and it fixed the problem. I usually drive home from the panel shops crying as a result of these quotes but at least I dont stink of fuel & exhaust fumes !!!!!!!!! 

[1750GT]

Guys another problem I have found is the two rubber gromets in the tyre well (there are two on mine, which seal the tyre well - not really sure why they are there, presumably your tyre well shouldn't fill up with water, but if it does, the gromets come out).

I discovered that one of the gromets wasn't sealing properly, fixed it and it largely fixed the problem. I am not sure the holes and gromet seals are standard on 105's? Does anyone have the same thing? the rubber gromets and holes are approx: 30 millimeter's wide.

1750GT

[pep105]

Yeah 1750GT mines got em as well, 2 of the bastards and one has a rust hole right of the edge of the grommet. I believe its standard on 105s, and aids water drainage, theres 4 in the floorpans as well and mines got rust on the grommets holes there too just for good measure. However did notice a huge difference when the boot was properly sealed

[Gary Pearce]

Firstly the two grommets and holes in the tyre well are standard on all 105's. If air can get through here, it would be positive pressure ie any petrol fumes in the boot area would have air pressure forcing the fumes somewhere usually into the cabin.
Secondly, it is my current belief that 105 petrol smells largely come from the fact that 105's have very elementary fuel tank venting systems, venting petrol fumes from the cap in to the fuel cap boot area and out around the filler flap door (negative pressure now). Trouble is the filler pipe boot very rarely seals the inside of the boot correctly these days due to cracks or simply poor sealing.
I am currently working on two of my cars with a trial venting system from the cap, which then vents fumes out the bottom of the car. I will keep you posted.

[lombardi]

Thanks guys for your very replys,i tacked the easiest job whiuch was to properly sead boot lid,you know what,i noticed the difference straight away,and i so much wanted it to work,the one about the tyre wells,ill have to look into it,i instantly dont know what u are talking about,i will investigate,another problem with fumes is that i like the drivers window open and that adds to the problem,i believe ther is a bit of a vacuum effect,keep replys coming,its much appreciated.ciao amici

[1750GT]

Lombardi, just lift the spare tyre out of the tyre well and you'll find the two holes in the tyre well with the rubber gromets (thats if the rubber gromets are still there, alternately you'll just find two holes in your tyre well).

By the way pep I didn't know about the pesky ones in the floor well, I'll need to have a poke around as this is definitely not good, thanks for the tip.

I do agree with Gary, all you have to do is have a wiff on the left hand side of the boot, mines got the original rubber cover boot and a feel around the edges shows that it's not doing much more than keeping the fumes in the boot. I'd be interested in the outcome of the revised venting system. This seems like a viable solution if it works, I understand the positive/negative pressure thing and the rubber boot problem but I would have thought that if you are not venting to below the car that irrespective of the boot seals, you'd still get fumes through into the cabin eg. thru the seats? As for the windows open problem, with this car I think your going to get a bit of that anyway. I have found that when I have the window open, and this might sound dumb, but having the front window quarter panel open at 45 degrees with the wind comming in helps, pressure of the wind comming thru the quater panel pushing the smells back out? don't know but seems to work.

Just remember Alfa's are not the only ones with this problem in this vintage of car. I can remember my old mans valiants, chev impala and fords (he was a mussle car freak in his early days) and my Escort RS200, Capri and Alfa  Guellietta (I was a small muscle car nut because if I wanted a big one I'd just drive my old mans and he'd certainly drive mine) having similar issues, I think the petrol used to smell better then though, don't know but seems that way?

1750GT

[lombardi]

Love your reply's,much appreciated.took out spare wheel out of boot and behold grommets are firmly in place but there are some tiny little holes in other parts of wheel well,so my answer,i got some muffler putty and blocked them up,its definitely sealed plus the reply about the window and quarter panel,i cant wait to try it,definitely whe are getting to the bottom of this,its improving with each answer i get.ciao and grazie tanto