Even when I have not filled up the tank in a week, when I walk around my 1999 4WD 4-Runner I smell gasoline. I have taken the dealership, but they claim there are no leaks. The smell is strongest on the driver’s side of the car, where gas tank is located, but I can smell it on the other side as well. I don’t think I am losing gas b/c my gauge does not drop quickly. Any suggestions?
dinnmarsh,
Some thoughts:
Do you have a steel or plastic fuel tank?
Do you live or drive in the “rust belt” where the weather gets really cold in the winter and/or they dump salt all over the roads?
Some vehicles can develop small leaks on top of a gas tank, fuel line or fuel pump/sender assembly, caused by rust, up there where you can’t see it. They start out very small and you might not see gas or notice increased consumption, just get the smell.
A bad charcoal canister, usually located near the tank, could be the culprit. It is part of the evaporative emmisions system and is supposed to hold gas fumes from your tank until you start the engine and they are drawn in and burned.
I think some techs use a hydrocarbon sniffer to sniff around in order to locate gasoline fumes.
I too lived in the rust belt and have replaced 2 gas tanks on US made cars. The leaks in both cases were around the gas filler neck where it entered the tank. In both cases, the gas evaporated before it had a chance to drip down to the bottom of the tank. So no gas on the garage floor, or visible from cursory inspection.
A bad charcoal cannister as per previous post, is also a possibility.
My old 1989 Caravan had a bad gas odor, and a master mechanic told me the problem was I was overfilling (click, click, click) the tank, then parking the vehicle. When the gas expanded as it warmed, it stuffed raw gas into the canister. On that model it cleared itself out when I stopped overfilling it, but until then it smelled terrible. I am told other models canisters may be ruined if you overfill the tank.
Another area to check are the fuel injector O-rings. There’s an O-ring at the fuel rail for each injector and an O-ring at the intake manifold for each injector. If any of these O-rings are leaking, the residual fuel pressure will allow gas to leak onto the engine long after the engine is shut off. And it doesn’t take much gas to create the odor.
Get a bright flash light and look at the injectors to see if any gas is leaking from any after shutting off the engine.
Tester