Fumes/petrol smell in cabin + Traveller rear boot floor

[nwxh]

For a while now (though I've ignored it in the hope it was related to other issues), there has been a smell of fumes/exhaust in the cabin on longer journeys. Is this just simply exhaust getting in through gaps in the back of the car or something more sinister?

I intend to take care of the rear boot floor (and at the same time check the fuel tank and rewire the back in case this is causing the above). What should I look for, or should I just replace all gaskets? The metal is a little rusty. Is it a case of sand with emery, spray on prime, then spray on black paint while I've got everything out the way?

Many thanks,

Nick

[SteveClem]

Similar recent discussion on this Nick that you might want to check out.

[nwxh]

Cheers. I checked the engine bay but not the fuel tank sender today.

The float chamber lid has new gasket but if I touch it I can smell petrol on my finger. Is this normal? Does it need to be even tighter?

[bmcecosse]

The fuel level may be too high in the chamber... Is it flooding over the jet?

[nwxh]

Not that I've noticed with the air filter removed. The pump clicks multiple times when the ignition is turned on if left overnight.

Is a normal amount of seepage to be expected for the float chamber lid gasket?

[bmcecosse]

No - have a look at the float valve. My car only clicks twice after overnight...is the base of the carb 'moist' ?

[nwxh]

I'll report back and have another look with the air filter removed. If I turned on the ignition with the engine off. would the overflow be out of the jet or just slow and hard to see seepage through the gasket?

I'm now wondering if I didn't clean the surfaces either side of the gaskets enough. If I take it off, should I sand it down with emery and put it back on?

[mowogg]

Is it unburnt petrol you can smell or fumes from the engine/exhaust?

[nwxh]

Hard to tell. Just now, I took it up a hill, and could smell it at the top. Couldn't inspect the carb properly in darkness, but there were traces of petrol and dirt on the gasket. The bottom feels a little oily but not moist.

Should the gasket stop all fuel leaking it? If it can't stop an overflowing chamber, surely fuel is going to spill out on hills and when the car is parked on one?

[bmcecosse]

The level should be low enough... But indeed the little gasket is there to avoid slops coming over.

[nwxh]

Thanks again. I checked it today.

• There are definitely only two clicks overnight based on journeys this week.
• After the two clicks (and igition off), I took the lid off today. The fuel was far from the top.
• The float looked fine
• The float successfully blocked air being blown through it when pushed up.
• The gasket was not at all stuck to the float chamber. The service is clean/free of dirt but rather rough with one bubble. I assume that this is just from the casting.
• The gasket formed a good seal to the lid near the screw holes but was otherwise loose. There was some dirt on the mating surface
• NB The gasket and floats are only two months old, replaced from earlier issues.

I assume that, at some point, I should get a new gasket (since I can't easily take it off without damaging it), soak the lid in carb cleaner overnight, and then put it back together?

NB I first smelled the smell on the day I bought the car and drove it back. I guess I expected that it was always an issue with such cars and other issues that developed took priority.

I note that the right side of the engine is "wet", especially near the top of the sump. However I don't know if this is petrol leaking down or engine oil seeping out. I assume I should deal with the float chamber, and if the engine never "dries", take off the sump?

[bmcecosse]

Wipe it clean and then see what comes out. 'Right side' - so around the dizzy/behind the dynamo ??

[nwxh]

Sorry left side. I've been under the bonnet too much. So under the carb.

[mowogg]

Hi -i have had this issue in the past. i found it was the valve in the float chamber. It looked fine, and worked fine on the bench, but for some reason intermittently over topped when in use.It seems very odd, but i guess they develop wear and can then get stuck mid travel

A new valve fixed it, and the issue did not return. It would be my recommendation to change this

[bmcecosse]

I thought so..... so is the little wire braid covered pipe from float bowl to carb leaking? Is it wet ?

[nwxh]

Not that I noticed. I assume that the two clicks after overnight is a sign that the leakage is sloshing/hill spill rather than a stationary leak?

[liammonty]

Given that your car is a traveller, I wouldn't be surprised if it's actually fumes from he exhaust coming in the back doors rather than actual petrol vapours. Two clicks of the fuel pump sounds fine to me. Try adding a short extension to the tailpipe (you can get naff chrome ones from car accessory shops) to lengthen the tailpipe. This worked well on my car, and I know it has for others too. Fume ingress is common through the back doors on a traveller. For the cost, it is well worth a try.

[nwxh]

Good suggestion. So it gets worse with the front windows open because the air comes in from the back and passes through to the front?

Maybe the carb always has a little leakage, especially as every journey here involves about 200m of hill. Will try and clean it to see what happens though.

[bmcecosse]

Been over this before - yes you can get exhaust - but it doesn't smell of petrol! Eye watering/throat hurting - yes - but not petrol smelling.....

[mowogg]

Two clicks of the fuel pump is normal. I would still suspect the float valve on tis one.