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2012 Subaru Legacy - Smells like gas

Had it in to the dealership once and to an independent repair service once to try to find the source of the gasoline smell in the car, It most commonly shows up right after starting, perhaps 50% of the time. The smell seems strong to me (and to my wife when she’s been in the car) but it abates after a few minutes. Outside of the fact that it smells lousy, I wonder about the potential safety hazard.

You might ask to leave it overnight so a mechanic can observe the symptoms. You should not experience that on startup.

I’ve done that already. The dealership said they couldn’t replicate it. I’m baffled!

Brock Putnam

In a message dated 1/18/2020 6:07:47 PM Eastern Standard Time, cartalk@discoursemail.com writes:

Then take it somewhere else. Gas is leaking from somewhere and that has the potential to be more than annoying.

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Is it only happening when cold? I got rearended a few days ago, and now when cold, like 0 degrees to 20 degrees so far gas smell on start up, the rest of the day is fine. I am probably going to get my car totaled by insurance, I am really thinking it is an exhaust leak. Maybe the engine runs rich at startup, and that is the only time after sitting overnight it happens. No sounds of exhaust failure, but my tailpipe is bent underneath the car rather than going out the back.

Thank you. I appreciate your response. It not only happens in cold weather, though. I’ll keep trying with repair shops. I’m giving up with the dealership - but I won’t get a dealership loaner while I explore the possibilities. This has been happening for a while now. (growl…!)

I

In a message dated 1/19/2020 5:55:19 PM Eastern Standard Time, cartalk@discoursemail.com writes:

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Possibly a leaking injector. In that case the fuel odor would be strongest at the tail pipe, assuming exhaust system is not leaking.

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Thanks! It’s due for the state mandated emissions test, so that might yield some information rather than me pestering the dealership again!

In a message dated 1/20/2020 10:21:54 AM Eastern Standard Time, cartalk@discoursemail.com writes:

From your description it sounds to me and @shanonia like you have a leaking fuel injector… And it is leaking INTO the engines intake manifold. Those are the only type of gasoline smell issues where the smell goes away.

Any fuel leak issue is a serious one…especially ones that leak externally due to fire hazard. External leaks smell all the time and the smell never goes away. A leaking fuel injector leaking into your manifold will pool the fuel in there…and it will also make its way into your crankcase which can dilute your engine oil making it less of a lubricant if this occurs at high volumes they call this “making oil” because your oil level will seem to magically rise on the dipstick.

Pull your dipstick and check your oil… is the level full? Over full? Does it smell like fuel? If it check out ok then the leak may be small…but its still smelly… and the smell will go away when the engine starts and simply burns the fuel.

Have your vehicle checked for suspicion of a stuck open / leaking fuel injector

Fuel injectors and fuel pressure dampers can have an intermittent, external leak, usually when the engine is cold. If it was an internal leak the fuel would be burned in the engine and you wouldn’t smell fuel unless it was causing a misfire.

This needs to be inspected during a cold start, may take several days to observe the leak when it occurs. An intermittent fuel leak will not be detected during an emissions test.

I agree with you @Nevada_545 about the fuel being burned…and of course it is… however a leaking injector into the manifold will manifest with a smell of fuel in the cabin of the vehicle temporarily until the engine is started and that leaked fuel is then burned…the smell will simply go away.

The pool of fuel…or its equivalent that was leaked into the intake manifold will stink up the intake tract and into the air filter…and under the hood…then into the cabin. When the engine starts it magically dissipates. Which is one reason some guys find these non obvious external fuel leak / smell issues so difficult to solve sometimes. They may miss the possibility of the leak being in the intake area…so they either discount it…or never consider it and thus… never solve it. At least that is how I wind up finding and fixing them in the end… lol

Another possibility is a defective Engine Temperature Sensor, which is causing the engine to run with too “rich” a mixture.

When my brother bought his new Hyundai Azera several years ago, he had the same problem, and it turned out to be a defective Engine Temperature Sensor. If one of those sensors can be bad right out of the box, surely it is possible for one to go bad after 7-8 years.

We had a fuel leak in a rusted fuel line. I took it in for an emissions test and smelled gas the whole time I tested it. Testing for us consists of reading the stored OBD-II data. The car passed, btw. We had it evaluated shortly after that. The mechanic couldn’t see the leak and had to do a smoke test to find it. Any time there is a gasoline leak there is a chance it could catch fire and spread to the rest of the car.

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