with out looking at the engine its hard to tell but i would say its coming from the rocker cover gasket if its topend only, rocker gaskets are very cheap and an easy diy job
Leaking injectors.
Very much so. Excess fuel caused by a leaking injector can wash the bore, this can cause a seizure. Also excess fuel can dilute the engine oil, again causing a possible engine seizure . And on a lighter note, leaking injectors can certainly damage the contents of your wallet.
Leaking injectors that are allowing fuel to flow after shutdown, will allow fuel to flow into the cylinder. This fuel will mix with the oil and dilute it's lubricrating ability. This will cause engine wear and will eventually cause serious engine damage.
coolant leaking into the engine
Coolant leaking from the pump shaft.Engine overheating.Noise coming from pump.Coolant leaking from the pump shaft.Engine overheating.Noise coming from pump.
Heater return pipe or hose, leaking intake manafold gasket.
Usually bad injector cups. Leaking fuel seals, fuel system restriction, and bad injectors are other possibilities.
If it's leaking from INSIDE the firewall (away from the engine compartment) you probably have a leaking heater control valve or damaged heater core.
the fuel is pumped from the gas tank into the "fuel rail" and the gas stays there until you start turning over the engine to start it. the fuel injectors take the fuel from the "fuel rail" and spray it into the cylinder which then gets ignited by the spark from the spark plug. so if the injector is leaking or not functioning the fuel will just flood into the engine if leaking, or not go into the engine at at all if its not working. the reason they went from carburetors to fuel injection is so less gas is wasted because the injectors only spray a precise amount of fuel.
Pressure test system to observe leak
V6 engine - 6 fuel injectors V8 engine - 8 fuel injectors
I would say you have a fuel leak. It can be at the fuel rail or any of the injectors or connections. This is a very dangerous situation. Have this repaired ASAP. A very slow leaking fuel system will not set the check engine light. http://www.autozone.com/servlet/UiBroker?UseCase=S001&UserAction=viewSimpleDiagInfo&Parameters=info