You need to find where it is leaking, it could be a loose connection, an old rubber seal, rust, etc.
Yes it can. If you look at the fuel pump you will see a medal plate that bolts to the engine block and the fuel pump sets against that plate. The plate and the fuel pump both have a gasket on them that stops oil from leaking out of the engine block. You also need to check the fuel pump, There is a small hole in the side of the pump that can leak oil out of it. If it is leaking you will need to replace the pump. Check the pump for oil leak while the engine is running.
fuel leak on top of what type of engine, gas or diesel?
Where is the leak at? Engine?
usually fuel injectors leak gas on the engine block and car missfire in acceleration, also consume more gas than normal
Where is the leak from? The fuel filler? The fuel tank? A fuel line? Does the leak occur only when the engine is running? Does the leak only occur when the vehicle is parked on an inclined surface?
An oil leak.
usually there is a fuel leak internally however it can also be an air leak
two things, exhaust has a leak of gases or fuel leak from engine bay
Find the leak and fix it.
There is gas pouring on the engine. You have a fuel leak.
The first thing to look for would be an exhaust leak. Check for a fuel leak on the top of the engine.
Restricted fuel filter, air filter caused by lack of maintenance. Internal or external fuel leaks. Check for an external leak in the valley of the engine, the cam driven fuel pump is in the center of the engine and has a tendency to leak. A internal leak would be a cracked head, check the coolant and oil for fuel contamination.