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Can loose gas cap cause EXTREME amount of gas smell?

I have a p0456 and I remember tightening my gas cap years ago and it’d just go away. Nowadays it stays on so today I went and just bought a new one. My question is can it make my WHOLE car smell super potent if gas? Like I can’t sit in the car with the windows rolled up for 15 minutes without my throat hurting from inhaling it.

Also it never smelled like this a year ago

Probably not. A leak at the tank, its filler tube, the fuel lines to and from the engine, or under the hood are more likely. Most repair places have a hydrocarbon sniffer that can detect leaks, although one as severe as yours probably has left a visible trail.

No sign of any leakage. Possibly internal?

Also I have an exhaust leask could tht b it?

If I can guess at this post, yes, that could be it.

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If the smell of gas is that strong, and the vehicle is parked in a garage, park the vehicle outside, and have it towed to a shop to find the leak.

Not normal.


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A p0456 is for a small evap system leak. That wouldn’t be enough to create a major gasoline odor. If it was the gas cap leak causing the odor you wouldn’t notice it anyway when sitting inside the car, unless you were in an enclosed garage or something. There are other problems that can smell sort of like gasoline. For example a oil, power steering, or transmission fluid leak onto a hot exhaust manifold creates a pretty noticeable petroleum odor. That’s something you could notice from inside the car. It’s possible the small evap leak code is a clue to what’s causing the noticeable odor, and sicne that’s the only clue you have , might as well use it. Suggest to get that small evap problem fixed, and while doing that job the shop may notice what’s causing the major odor problem. If I had a car I couldn’t sit in for 15 minutes without my throat hurting, I definitely wouldn’t continue to drive it.

Naw I think you’ve got a leak somewhere. Even when I had a rust hole in the top of my tank, the only time I could smell it is if I filled it up and it was in the garage. Of course I replaced the tank. Really though it could be in the engine compartment which would be very dangerous.

It’s likely you have a gas leak somewhere in the engine compartment, and it’s dripping on to something that gets hot, and vaporizes fast. You may never see a drip or a trail because the gas never gets very far, but it will stink. It’s also very dangerous. Vaporized gasoline is very explosive. That’s what runs your car.

UPDATE. Im leaking gasoline like crazy now! i think its a broken fuel line. Could this be why my care is hard to start? maybe not enough fuel reaching the engine???

For Pete’s Sake , have this thing towed to a shop and have the LEAK fixed. And if that doesn’t solve the starting problem then you will know to keep looking.

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im getting it checked tommorow. im just asking if this is a probable cause for the hard start

If the leak is in the line between the pump and the fuel rail, yes, that could depressurized the fuel rail and cause a “cranks ok but takes a long time to catch and run” problem.

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Amen to that. When the car goes up in flames and maybe takes the house with it, hard starting will be the least of your concerns.

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i had just realized today that im even leaking gas :rofl: you think im actually going to drive it now knowing this lmao

Gas fumes seek the lowest level like the garage floor, and then can creep along to things like electrical devices that spark or water heaters and fireplaces with pilot lights and BOOM. Maybe push it outside at least ready for the tow.


its in driveway. getting looked at tommorow

I hope that your driveway is made of concrete, rather than asphalt.
Gasoline dripping on asphalt softens the asphalt and causes permanent damage.

You are getting it towed, hopefully. Although perhaps the tow truck operator will be reluctant to tow a vehicle dribbling a trial of gasoline behind it. And onto his truck.

There is a VW specialist shop in my area and one of its customers failed to mention to the shop owner that his old Beetle had a gas leak. The mechanic was welding another car in the shop when the gas fumes from the old Beetle ignited, and the shop burned to the ground–along with all of the cars being repaired.