on my 1995 taurus se when i start it you hear what sounds like a hollow knock coming from the driver side of the engine compartment you can hear it underneath the car to. it sounds the worst around at idle and when i get it up to 1500+ you cant hear it anymore in drive you hear it at low speeds too i checked all the fluids and checked to see if anything was loose and i can not find it. the car has had a recent rebuild on the upper half of the motor due to some water getting into the intake and it has a 3.8 v6 i need this vehicle so i can go to work because my truck has horrible gas mileage can some1 help me.

 

Listen to the motor and see if it sounds like the knocking is coming from the valve cover. Sounds like it could be the valve lifters?