Fuel Smell in the Cockpit

By Roger Moment Boulder, CO

Originally published in the Austin-Healey Magazine, January 2000

Q: Recently when I got in my Healey, I smelled fuel. I never noticed it before. I can't see any obvious leaks and there are no fuel puddles on the ground under the car. What could it be?

A: If the car has been odor free for some time and just recently began to smell of gas I'd check the following:

1. Check the fuel pump, specifically check around the seal between the solenoid and fuel pump body

2. Check the joint of the flex fuel line to solid line, down by the front frame, including the short hose that connects the flex line to the solid line.

3. Check for wetness at the banjo fittings to the carburetors.

4. Check if the float bowl valve is not shutting off. The evidence of this fault would be if the fuel pump doesn't stop clicking when the ignition is turned on and the engine is not running.

5. Check the flexible fuel lines for possible cracks and leakage.

6. If all the above checks out OK, I would suspect that you might have pinholes in your gas tank. To check for this, put some dry paper towels down in the narrow gaps between the gas tank and the boot floor. See if they soak up any fuel. I once had a gas tank that started to leak on the bottom, and it was not noticeable at all from the top. It was caused by rust that started due to water accumulating on the boot floor. This is not an uncommon problem. It is also possible that a leak could occur at the drain plug on the bottom of the tank. A leak here can be so slow and of such small volume that the fuel can actually evaporate before it forms a drip. Check for a damp spot or traces of a fuel stain.

If you can't find a leak at any of the points noted in 1‑5 above, and it appears that pin holes in your fuel tank may be the cause, you'll have to pull the tank out and check it carefully. There is a drain plug on the bottom of the tank that is visible from under the car. That will allow you to empty all but a quart or so of gas and will make it much easier to lift the tank out.

By the way, be extremely careful when dealing with gas. The fumes are explosive. Have a large pan available to collect the gas and proper gas cans and a funnel for transferring it to a safe container for storage. Do this outside to assure proper ventilation. Also, you may need to jack up the car at the rear, so have two jack stands available. Raise the car just enough to let you get at the drain plug and put the pan underneath.

Also be sure to treat the fuel line fitting with respect. It is a British thread and the brass hex nut can become damaged if not worked carefully if you find it on really tight.

Of course, you also shouldn't overlook the simple possibility that you or someone else may have spilled some fuel in or on the car, such as on the Armacord lining of the boot or even the carpet or seats on the interior. If you keep rags in the car don't overlook the possibility that one may be gas soaked and could be the source of the odors.

The bottom line is that fuel leaks are not just a source of annoying odors, they can also indicate a dangerous fuel leak. Checking the integrity and condition of the entire fuel system, from the filler opening to the carburetors, is a good way to solve or prevent many potential problems.

Not what you were looking for? Don't forget you can check our back issues using the AHCUSA Magazine Index.