The 4.0 is not a quiet engine by any means, mine sounds like a sewing machine at a sweat shop. But if it just started making noise, take a look at the exhaust manifold for leaks, make sure the oil level is full, and basic thing like that.
Steering stabilizers will not cure or cause death wobble, they only mask the real problem that is causing death wobble. Oil pumps do not make pressure, they create flow. Bearing clearence and restrictions make pressure. It's the crank sensor.