Despite my current efforts I simply cannot track down the fuel smell in the boot and the cabin, it’s doing my nut in.
It can only be smelt when it’s been sitting closed for a while and it disappates. The engine bay doesn’t smell of anything. The car smells a little bit worse when it first starts up like this but doesn’t have any smells once it’s running (always a good thing.)
I’ve looked at and prodded the fuel tubes in the boot quite thoroughly and although they are a bit rotten with what I think is mould (white splotching on the top part, the boot has had problems with its water seals thanks to the luggage rails on the lid not being watertight) they appear to be on tight enough and properly, and craning my nose in to smell the tubes doesn’t make me think the smell is coming from there. I’ve ordered a replacement whole fitting because I don’t like the tube rot, hopefully it also solves the issue but I don’t have high hopes.
I haven’t lifted the car up yet but below the car is bone dry so I’m not sure I’ll see anything unless it’s a leak that’s dripping onto the exhaust (?)
Is there any other really obvious place I should check that I’m missing before I start thinking about trying out the UV dye method of leak detection? I’ve already triple-checked the bloody filler cap!!!
It’s especially annoying because there’s nothing really else wrong with the car other than this, I’ve even sorted out the wobbly idle from cold (idle ambient setting was too high) and I still haven’t sorted the CAS O-Ring out (leaking), done an oil change, any of the filters, the PCV valve… only other thing is that the coolant resevoir is empty but the radiator isn’t, so that needs filling and hopefully it’s not a leak.
Theres a drain hole next to the filler neck with a hose attatched that runs through the boot & exits underneath. If thats blocked or as in my case on my old Sport, become unnatached at the top inside the boot you will get a strong wiff of petrol.
Youve probably already checked that but its worth checking if not. Hopefully it`s something simple & not a fuel tank leak!
Hmm! I checked it earlier and it seemed connected but somehow I didn’t think to check it for blockages. I’ll give that a poke tomorrow, cheers.
Given the location of the smells, lack of leaks and all that, some more reading on miata.net told me that the rubber on those fuel hoses has a hard time dealing with the ethanol in the fuel and it starts to make the hoses smell. Thankfully I already have a new fixing with tubes coming because I didn’t like the look of the tubes currently, so either with your suggestion or that replacement, I’ll have this smell beaten.
i don’t think your the only one, mine stinks if left for more than a week, everything seems fine so i’ve not even bothered to find out why
Mine starts to smell really bad in a few hours. Sure, I could live with it, but I bought my MX5 long before I need to rely on it as my daily driver (my current car is a lease purchase and goes back in November, so tons of time) and I’m using part of the long gap to go to town on the car and perform a mini-renovation. Having just cleaned all the carpets and surfaces, tidied up the electrics and have started to chase down engine gremlins to get some of its performance and economy back, my perfectionist self is extremely irritated by the smell! I’m worried that anything I leave in it will start smelling of fuel, especially in the boot!
This morning I ran a glass of water down the fuel cap drain hole and it drained out the bottom instantly and easily, no leaks in the boot or any dampness at all. Drain hose ruled out - when the fuel filler hose fixture arrives I’ll change that out and see if that cures the ills. I’m becoming convinced that the hoses themselves are the problem, they may be vapour tight to their respective fixings, but the tubes are old and rotten and I suspect they’re emitting the fumes themselves. I’m not seeing anything on the underside of the tank or the fittings to suggest a leak anywhere else - if the fuel line replacement doesn’t help, I may have to start looking at the UV dye route… groan.
Hi My fuel filler cap seemed ok, but to be sure I bought a cheap one, after a few days no more smell of petrol in the car, so bought a new masda cap all ok now.
2001 MX5 2.5 black Auto
After a run loosen the fuel cap, if it blows pressure it is Ok, if not it needs replacing
It has been depressurising on loosening the gas cap after running the engine so I think the gap being faulty is not the issue.
I’ve bought and have had delivered a replacement fuel pipe + hoses fixture from MX5Heaven (the entire part in the boot that runs from gas cap to fuel tank) and I’m going to replace that this week and see if that cures this once and for all. Will report back…