Only during Accelaration. Scott-
your engine is loud because, the fan makes that noise
Having a bad rod bearing could cause a truck to make a loud knocking noise and shake when driving at high speeds. The engine having a coolant leak or an engine timing problem could also cause the knocking noise.
It is POSSIBLE, but highly unlikely unless you had prior problems with the timing. I would have it checked out by a mechanic as it could be any number of things.
If you are hearing a loud popping sound from your carburetor while the engine is running, then that is engine back fire. It is possible that your timing is off at the distributor if it happens often.
If the 1999 Suburban noise is a sort of loud banging noise, the problem could be that the engine have jumped time. Jumping time would cause the noise and jerking in the engine.
The fuel in the cylinders exploding
i have a very loud tapping noise in my BMW 318i e36 1993 engine. its extremly loud on start up then drops down to very loud when idling. the noise never goes away. I've had people say the engine was about to throw a piston, i need a new engine, etc what could it be and is it possible to fix?
Muffler
You have to locate the source of the noise then repost your findings.
Loud engine noise is usually a result of a hole or disconnection in the exhaust manifold or muffler.
It would depend on what part is making the loud noise. We are going to need more info.
Stuck hydraulic lifter.