Gasoline smell outside of car

[Bamaguy]

Ever since I bought my 2012, I noticed a mild smell of gasoline outside of the car - usually more noticeable after driving it. I always parked outside so I didn't think much of it, but now I have a house with a garage and a gas water heater in the garage, so I'm going to need to address it.

There are no visible leaks and when I pop the hood, the smell is not stronger there - just outside the car. There is no gas smell inside the car and it is not related to whether I just filled up the tank. I read some threads about the charcoal cannister, but it sounds like most of those folks are getting their smell inside the car.

After a little more research, I thought I should add a couple of things. I don't smell anything when I'm driving - windows up or down. Never a smell in the cabin. She is running awesome. The car does not have test pipes or aftermarket cats to my knowledge. I am thinking or ordering a new vapor cannister and solenoid, but I wanted to wait to get some feedback here first.

Anybody have any thoughts on this?

[Robdukes]

I get a mild gas smell when driving with windows cracked. I attribute it to the cats.

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[mys4.org]

Smell the exhaust while it is running... Does it smell like a lawn mower? If so, your cats are done or removed themselves at some point.

[Bamaguy]

Smell the exhaust while it is running... Does it smell like a lawn mower? If so, your cats are done or removed themselves at some point.

If the cats were toast wouldn't it be running rough or even throw a code?

[Bamaguy]

I have checked the exhaust pipes and there is no silver dust of any kind. In fact the exhaust soot looks very healthy. Since I haven't gotten any other input I'm going to go with the vapor canister and solenoid. Hopefully that fixes the problem. I will check back in after I do that installation.

[B7TitaniumA4]

Just a thought,

When you fuel up do you pump until it won’t pump anymore? Like fill to tippy, tippy top? It’s possible your charcoal canister is getting fuel in it, though it would most likely throw a CEL.

I used to click, click, click in other cars. The S4 clicks and I go to nearest whole cent and done.

Liquid Fuel in the charcoal canister prevents the evap system from working properly and can damage sensors that are only designed for vapor.

Good luck.


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[mys4.org]

If the cats were toast wouldn't it be running rough or even throw a code?

Most often they would get a code, but still what does your exhaust smell like when running. If you don't smell it in your exhaust then you got a fuel or vapor leak somewhere. Honestly just get under you car and sniff around until you find where it is the strongest. Don't forget to pull up the rear seats and smell around the fuel pump. Can't say this is a common issue, but maybe the fuel pump cap is cracked or needs to be tighten.

[wrxkyle]

pretty simple routing, pull the rear seat and remove the 3 screw cover and smell and inspect around there for leaks or cracks. esp on a full tank as the fuel level will be higher than the lid. there's a couple quick connects there, one to the tank and one from the (semi hard plastic?) line to the body hardline iirc, then there's just the hardline connection to softline in the passenger side engine bay strut tower, at the passenger side map sensor by the supercharger and the hpfp.

there's also a possibility of a vapor canister solenoid i'd guess.

raw fuel smells distinct from exhaust fuel smell but it's not uncommon for the cats to blow (and take your motor with) or just gut themselves over time as they fail. it's not a pleasant smell but it doesn't smell like a spilled gas can either.

[Izzyz28]

Before throwing parts at it, check the top of the fuel tank/pump under the passenger back seat, as well as the fuel line quick-connect fitting on the passenger side of the supercharger before it heads to the HPFP. If anyone has ever loosened the fuel pump lock ring and not tightened it down way past what you think it should take to seal, it'll leak, even on an empty tank.

[Bamaguy]

Update - thanks for most recent replies. The smell is most noticeable on the driver's side. No smell in cabin unless I open the driver's window while parked. Smell is like fresh gasoline like from a gas can.
@mys4.org - exhaust smells as would normal with functioning cat. Will pull up rear seat this weekend and inspect.
@wrxkyle - as mentioned will pull rear seat this weekend and inspect all of that. Thanks for detailed info on what I'm looking at under there.
@Izzyz28 and @wrxkyle - I will also check under the hood at the fuel line fittings.

All of this will have to wait until the weekend, but I will report back. Thanks!

[Bamaguy]

Well, I am still waiting for a part, but I had to do the rear brakes today, so I got under the hood to check the fuel fittings. I really stuck my nose around in there and it seems like the smell is coming from the center rear of the engine. I had already ordered the vapor canister purge solenoid which sits right there, but they sent me the wrong one. It really just smells like raw fuel. I don't have a good diagram of the hpfp and the connections for it, but there was no smell at the front of the engine.

Any thoughts? Anybody have a good diagram of the hpfp and the connections there?

[SForePlayin']

Now that you're smelling fuel under the hood, do you know if your fuel rails and seals have been replaced under the recall?

[Bamaguy]

Now that you're smelling fuel under the hood, do you know if your fuel rails and seals have been replaced under the recall?

Thanks for that tip. I called a local Audi dealer to look up my VIN and apparently that fix was done already several years ago. I have to keep digging.

[hgparrish]

Fuel lines come into engine bay on B8S4 on passenger side strut. Behind air filter box. Hard lines to flex lines. Trace them to front of engine HPFP, the goes to metal high pressure fuel lines under Super Charger to fuel rails. There are two nuts that should be torqued to 40nm that often leak if not torqued after replacing PCV valve or injectors.

Id pull your S/C and see if you have a leak there or bad ORing on fuel injectors.


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[Bamaguy]

Thanks for that tip. I am waiting to receive my new purge solenoid in the mail and then I will be getting back in there to do several items.

[Bamaguy]

UPDATE - This past weekend, with all parts in hand, I replaced the purge solenoid, the vapor canister and the leak detection pump. And I also tightened the HPFP bolts. After a very spirited test drive, I am happy to report that it appears the problem is resolved - no discernable raw fuel smell. I can't tell you which part did the job or if it was a combination of things, but I can say that I when I disconnected the hoses on the vapor canister, there was a great deal of back pressure.

The vapor canister/leak detection pump job was very easy and the purge solenoid and HPFP bolt tightening jobs were super easy (that is one degree more of easiness than "very" easy :D).

PS - please note that if you have to tighten the HPFP bolts on your car you need a triple square bit.

[LYKUNO]

Congratulations on your perseverance and success, and for providing feedback on what you did to resolve the issue. We don't always hear back from posters with problems on the actions they took to fix to problem, so we appreciate your feedback and recommendations. May you have many more thousands of problem free driving!

[evanb]

Congratulations on your perseverance and success, and for providing feedback on what you did to resolve the issue. We don't always hear back from posters with problems on the actions they took to fix to problem, so we appreciate your feedback and recommendations. May you have many more thousands of problem free driving!

^ +1

[Bamaguy]

Well folks, I may have spoken too soon. Tonight after work, I backed it out of the garage to wash it in the driveway and the check engine light was on. When I pulled it back into the garage, I smelled raw fuel again. This time a very small amount - much less than before but still there. This time, right around the general area of the oil filter housing. I didn't really have time to dig into it tonight, but I will get my scanner out and check codes to see if it's anything related and then get back under the hood to check some more.

It's strange because during my test drive over the weekend, I really got on it - like seriously stomping on it over about 15-20 miles on deserted back roads. It ran so great - almost like it was uncorked with all the new vapor equipment. And when I got home, no gas smell at all - just happily hot engine. I'm a bit baffled, but I'll keep sleuthing.

[SpeedyG]

Well folks, I may have spoken too soon. Tonight after work, I backed it out of the garage to wash it in the driveway and the check engine light was on. When I pulled it back into the garage, I smelled raw fuel again. This time a very small amount - much less than before but still there. This time, right around the general area of the oil filter housing. I didn't really have time to dig into it tonight, but I will get my scanner out and check codes to see if it's anything related and then get back under the hood to check some more.

It's strange because during my test drive over the weekend, I really got on it - like seriously stomping on it over about 15-20 miles on deserted back roads. It ran so great - almost like it was uncorked with all the new vapor equipment. And when I got home, no gas smell at all - just happily hot engine. I'm a bit baffled, but I'll keep sleuthing.

Please let me know what you find. I think I have the same issue but can't tell since I went Catless awhile back. It may be my Charcoal canister evap is shot as I was one of those guys that filled my gas to the limit with click, click click on the pump!!!