I have a 2002 Honda civic 1.7L. The car started to make a deeper sound and at idles with heat on, it smells fuel inside the car. Not sure if related, I recently went camping, I parked the car on a side road with some high grass. In the afternoon, I came back to the car. The fuel panel was forced open, the cap was still on.

Not sure if someone tried to syphon the fuel or what. I'm not losing any fuel AFAIK.

It smells like it is coming from the front of the car and not the rear but not 100%.

Edit: If I run the car at idle and I set the 'air recirculation' on there's no smell inside the cabin.

  • Have you checked under the hood if there are any signs of liquid around the engine and hoses? Maybe also smart to get another person, without telling, to get in the car with the heating/fans on and ask them if they notice anything. It could also be your mind playing games :) I don't think you should be able to smell gasoline inside, if they forced the panel open.
    – Paramone
    Commented Sep 20, 2018 at 12:11
  • 1
    BTW, Welcome to Motor Vehicle Maintenance & Repair! Commented Sep 20, 2018 at 12:32
  • @Paramore I've checked under the hood, no leaks or anything. I've had someone in the car and they noticed the smell too. By the forced panel I mean if someone was messing with the car. Trying to syphon fuel and they'd push air and increase fuel pressure. I'm not losing fuel so that's good.
    – Lazik
    Commented Sep 21, 2018 at 10:04
  • It ended up being the muffler. It was idented from the inside. It created a back pressure to the engine manifold and fumes were leaking from there. When I removed the muffler. It was full of liquid, lots of black fluid flowing out - yuck.
    – Lazik
    Commented Oct 8, 2018 at 13:59

2 Answers 2


Could be a fuel leak anywhere from the injectors, back to the tank. Check all fittings, o-rings, as well as rubber and metal lines. I had a similar issue on a different vehicle, and it ended up being a pinhole in one of the evap lines. Mine was the hose between the gas tank and charcoal canister that could be seen once removed.

Edit: Since you mentioned the possible siphoning, the hose(s) that connect the fuel filler neck to the tank could be damaged, disconnected, or loose.


If you are driving with the heat on, not recirc, and you smell fuel, it's coming from the front of the car. The cabin air intake for most automobiles is right in front of the windshield.

You wrote that the car now makes a deeper sound. That could be damaged exhaust and if there is a hole in it before the catalytic converter, the car would give off an odor of unburned fuel.

An open intake system also makes a deeper sound. Your PCV system routes blow by gasses back into the intake system (manifold usually) and the gasses from here have an odor of unburned fuel and hot oil. If a PCV line was disconnected, there might be some sound out of that and odor.

If the odor is that of raw fuel instead of unburned fuel, it only takes a very small amount of leaking fuel to have a detectable odor. You will have to check the system from the fuel rail back to the tank while the system is running like @Mobius described above.

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