Gasoline Smell - 1966 L79

[Edmund C.]

Gents: A happy 2017 to you all. I need some guidance. My 1966 L79 leaves a fairly heavy oder of gasoline in the garage after I take her out for a ride. She's fully serviced (e.g., recent tune-up, replaced cardboard gasket on gas cap, etc.). Any thoughts on what could be the source of the smell? It doesn't bother me, however, I'm concerned from a safety perspective. Many thnaks. Best, Ned

[Michael J.]

Re: Gasoline Smell - 1966 L79

Ned, look very closely around the carb base, intake manifold, and fuel pump lines in and out, as well as the gas sending unit on the bottom of the tank. If you see dried gas stains, or if you see any fuel leaks, that would be it. If you don't, remember that heat and humidity variation can make gas smell more intense or less intense from the fuel that just sits in the carb in a closed garage, and everyone has a different sensitivity to smells too. If no leaks or signs of leaks, I would not worry about it.

[Edmund C.]

Re: Gasoline Smell - 1966 L79

Mike: Thanks man. Will do. How is that cool tow vehicle of yours doing? Best, Ned

[Michael J.]

Re: Gasoline Smell - 1966 L79

Still running like a beast on steroids.......... Happy New Year!

[Joe R.]

Re: Gasoline Smell - 1966 L79

Ed,

Hard to diagnose on the forum cause there could be several causes.

1. Leaking at the tank sending unit.
2. Hose from tank to fuel pump.
3. Carb leaking (Holley's are bad about that).
4, Fuel Pump leaking.

Gotta check the above first.

Now make sure you check and make sure you don't have an exhaust leak heating up the tank!!!!! This could be lethal on the road or in the garage. I have seen the gas boiling in the tank! I ran fast!

JR

[Edmund C.]

Re: Gasoline Smell - 1966 L79

Joe: Yikes, I'll be sure to do that. Appreciate the guidance. Best, EWC

[Gene M.]

Re: Gasoline Smell - 1966 L79

Keep in mind the tank is vented.

[Joseph S.]

Re: Gasoline Smell - 1966 L79

Ned, Try shutting the car off outside the garage and letting it cool off. Then bring it into the garage after it has cooled. You may just be smelling the fuel evaporating out of the carb bowls. Because of the low boiling point of current gas along with the high heat of the engine after its been driven then shut off you will get some residual fuel smell.

[Frank D.]

Re: Gasoline Smell - 1966 L79

Check the gas filler neck if you haven't already - the original style gasket deteriorates along with the screws with the rubber "O" ring seals. That was the smell in my '63 coupe. Gas sloshing around after a ride exacerbates the smell...

Easy fix.

[Edward J.]

Re: Gasoline Smell - 1966 L79

Ned, Try shutting the car off outside the garage and letting it cool off. Then bring it into the garage after it has cooled. You may just be smelling the fuel evaporating out of the carb bowls. Because of the low boiling point of current gas along with the high heat of the engine after its been driven then shut off you will get some residual fuel smell.

Ned, Joe has hit the nail on the head, one of the most common issues with Holley Carb.s and AFB'S The fuel in carburetor tends to heat soak after shut down and tends to vent anywhere there a way for vapors to escape. this last summer I had a 66 doing this very thing, But also do a visual inspection as others have posted.

[Joe L.]

Re: Gasoline Smell - 1966 L79

Gents: A happy 2017 to you all. I need some guidance. My 1966 L79 leaves a fairly heavy oder of gasoline in the garage after I take her out for a ride. She's fully serviced (e.g., recent tune-up, replaced cardboard gasket on gas cap, etc.). Any thoughts on what could be the source of the smell? It doesn't bother me, however, I'm concerned from a safety perspective. Many thnaks. Best, Ned

Edmund------


Of course, you should check for fuel leakage as others have described. However, the problem here often results from "changed expectations". In the old days, the aroma of gasoline in the garage after a car was driven and parked was what I would call "a normal expectation". As the years went on, though, things changed. This actually began in 1970 with the introduction of evaporative emissions control (EEC), then applicable only to California-delivered cars. This was rapidly phased into all US cars. As time went on, EEC became more-and-more effective and sophisticated. Since 1996 with OBD II, if there's even the slightest compromise of an EEC system, a code is set and the "service engine soon" light is illuminated.

So, we've come to expect that there will be no gasoline aroma in the garage. That's the "norm" now. But, it wasn't always the norm and it's certainly not the norm for pre-EEC cars, then or now.

[Leif A.]

Re: Gasoline Smell - 1966 L79

Ned,
All the above. If the strong smell of gasoline is still there the next day, then I would say you have a leak somewhere. The normal "after driving" gas smell should dissipate overnight.

[Georges C.]

Re: Gasoline Smell - 1966 L79

Had the same problem until I replaced my original gas tank cap, unfortunately. But I did replace the sending unit twice until I lubed the sending unit as suggested, prior to installing.

[John D.]

Re: Gasoline Smell - 1966 L79

Ned, Try shutting the car off outside the garage and letting it cool off. Then bring it into the garage after it has cooled. You may just be smelling the fuel evaporating out of the carb bowls. Because of the low boiling point of current gas along with the high heat of the engine after its been driven then shut off you will get some residual fuel smell.

I agree. A good way to check would be how long it takes to start after a hot soak say five minutes or so. If it takes a while you know the bowls are dry. Wiring open the heat riser helped a lot on my 67 L79.

[Mark E.]

Re: Gasoline Smell - 1966 L79

Edmund------


Of course, you should check for fuel leakage as others have described. However, the problem here often results from "changed expectations". In the old days, the aroma of gasoline in the garage after a car was driven and parked was what I would call "a normal expectation". As the years went on, though, things changed. This actually began in 1970 with the introduction of evaporative emissions control (EEC), then applicable only to California-delivered cars. This was rapidly phased into all US cars. As time went on, EEC became more-and-more effective and sophisticated. Since 1996 with OBD II, if there's even the slightest compromise of an EEC system, a code is set and the "service engine soon" light is illuminated.

So, we've come to expect that there will be no gasoline aroma in the garage. That's the "norm" now. But, it wasn't always the norm and it's certainly not the norm for pre-EEC cars, then or now.

I echo Joe's input. The challenge is determining if the smell is normal venting from the tank and carb, or from a leak which requires repair.

Adding to the uncertainty is that the level of aroma varies with air temperature, humidity, engine temperature, size of the garage, and your sinus congestion. For example, I notice the stink from my pre-EEC 1970 more sometimes than others, yet I'm fairly certain it remained in good working condition.