I have a 1998 chevy 1500 350 v8 5.7L vortec that leaks oil in the front I have narrowed it down to the timing cover or intake and I suspect both and also the truck back fires through the exhaust. Is there any tips and trick to the intake gasket and timging chain cover gasket there is also oil all over the driver side engine aera in my oil fill cap there ius yellow white and brown stuff in it as well. Make sure to change the oil and filter as well.
In the oil cap if you have brown andyellow stuff then you are probably leaking the intake gaskets which these are famous for. When you replace the gaskets, put a bead of silicone on the china walls front and back and a little on the edge of the gasket in the corners. Make sure you mark the distributor andreset it to the same spot otherwise the engine light may come on due to that being the cam sensor and they can get out of whack with the cranks sensor.