the purge valve on the gas line is rusted inside. It is located inside the left front wheel well behind the cover. Easy to replace. check YouTube for video.
sounds like an exhaust leak, or a fuel leak. that depends on the smell.
The cause of cabin fumes on my VW was a breach in the CRANKCASE VENTILATION system.Brittle plastic connections and or tubing failure allows vaporized emissions to pass virtually unobstructed from engine-bay through cabin-air intake. There was also excessive oil leak visibal near filter-housing.
two things, exhaust has a leak of gases or fuel leak from engine bay
The primary cause of gas fumes in a Ford Expedition is a leak in the gas tank or vent. This allows fuel vapors to enter the cabin and poses many health risks.
a lot of things mostly a leak of some kind
A manifold leak is usually in reference to a failure of the intake manifold gasket. It can leak air, oil or coolant. It can leak to the outside of the engine or internally into the engine. A manifold leak may also refer to the Exhaust manifold that is leaking exhaust fumes from a bad gasket or a crack in the manifold.
is there any odor..??/ a small leak in the heater core will allow glycol fumes into the cabin.....this would smell sweet.
If exhuast leak exists at manifold or front pipe the fumes will usually be blown away when the car is moving (unless a fresh air vent is open) but when standing fumes more likely to find way into cab.
The first thing to look for would be an exhaust leak. Check for a fuel leak on the top of the engine.
power steering fluid
If you smell gas fumes you have a leak. To fix it you must find the leak. Your nose is your best tool to find the leak. This can be very dangerous so I would find and fix the leak ASAP.
Could be any number of places. We need more info like what type of leak such as a coolant leak, engine oil leak, exhaust leak, transmission oil leak, brake fluid leak, vacuum leak, rain water leak getting into cabin, etc.