Have you noticed the smell of petrol while driving? It's a worrying sign, but in most cases it can be remedied fairly easily.

There are three common reasons:


  • Petrol vapour from a leaking petrol cap
  • Liquid petrol leaking from a fuel injector
  • Petrol dripping from under the car/exhaust


Petrol cap

Petrol caps are supposed to seal the fumes from the tank, but if the cap is loose, you may smell petrol. This can happen if the rubber seal is damaged or if the valve is broken.


Solution: Replace the petrol cap.


Charcoal evaporation canister

Charcoal evaporation canisters are part of your car's anti-pollution system. They are located under the bonnet. If you can smell petrol from a canister, it is probably faulty.


However, some canisters are located on top of the petrol tank. Gaining access can be tricky and normally requires removing the tank.


Solution: This may well be a job for a trained professional.


Leaking petrol

Look under your car and check for any petrol dripping on the ground. Check the fuel filter, hose connections or any rubber component. Check directly above any patch of petrol.


If you can't pinpoint any leak, follow the fuel line up to the fuel injection rail. Because petrol is a solvent, you'll be able to see where any leak is coming from; there will be a clean, shiny, wet area where the leak is. You may find, for example, that one of your fuel injectors is clean and wet with petrol, while the others are grime-covered.


Solution: Visit your local mechanic.


Other ways to find leaks

Sometimes the leak is not immediately apparent. In this case, you could add UV dye to your petrol tank. After running the engine, the UV dye will appear where the leak is.


Exhaust leak

Run your engine then smell your exhaust. If you smell petrol, your engine is not running as it should. There are a number of possible reasons for this.


Solution: Take your car for a tune up to determine and solve the problem.