- My model of MX-5 is: Mk1 Eunos Roadster 1992
- I’m based near: London Borough of Sutton
- I’m looking for technical help or recommendations on: I wonder if anyone can shed some light on the problem I have with a petrol leak which has been flummoxing not only me but the rescue repairers. 6 weeks ago I filled the tank with petrol before parking it in my garage. A week later I opened the garage to a smell of petrol; reversed the car out to find a small puddle of fuel under the front driving side behind the front wheel area. Called rescue repairs who had the car for a week and could not find the origin of the leak. Drove the car home, parked it in the garage and left it for at least 3 weeks. When I came to use the car again - there was a smell of petrol inside the garage and on reversing out noticed a puddle in the same place as before, but on this occasion petrol was pouring down from the back of the car, in front of the driver side back wheel/archway. The car is now back at the rescue repair shop and has been for the past week, but they still cannot trace where the the leak is coming from. On both occasions of rescue, when the car was re-started to drive it onto the rescue truck there was no sign of any leak! And no subsequent sign of any leakage once at the repair shop!
At the moment I do not feel confident about driving the car until ‘whatever’ has been found so any ideas I can pass onto the repair shop would be great.
‘Filling the tank with petrol’
It’s been warm, is it expanding in the tank causing it then to leak out, have they got an overflow pipe for this reason?
Someone may offer an explanation better than this.
The fuel filter is under the car in front of the right rear wheel, under a plastic cover. A puddle below there might be either of the hoses which push onto the filter. There’s a hard fuel line leading forward from the filter to the engine bay and i guess it’s possible fuel might have run along that and dripped off the other end on the previous occasion.
But then of course it’s possible the leak is at the other end and the drips ran the other way. And there’s also the return fuel linee going the other way, which ive never investigated.
My gut feeling is the hoses on the fuel filter are likely culprits simply because they get pulled and twisted each time the filter is changed.
I’ve come across similar on other makes of cars where the owner has filled their car, often before a long journey and when the petrol pump had clicked off, they have resqueezed the trigger too top off their tanks and have done so several times and in doing so have lost the expansion room in their cars fuel tank. When the fuel in the tank expands it floods the carbon canister which is often located at the front of the car and leaks out the breather hole causing a leak at the front of the car.
The second leak may have been caused by the garage checking the connections on aging pipes.
Interesting as carbon canister also came to mind for me too. I can’t remember what side of the engine it’s on for the Eunos
The charcoal canister is on the right side of the car. But its vent tube plugs into the front subframe (for reasons ive never established) and so liquid draining in there would emerge wherever there’s a hole at a low point.
Interesting idea that an overfilled tank might flood the canister though I’ve never come across it in years of brimming my own (fill till it clicks off, pause half a sec, fill again just to check the first click wasn’t a false alarm).
Thank you to everyone who responded, it was very helpful. The hoses have been replaced and so far no further petrol leak 