knocking noise

When does it occur? Driving? Standing still with the engine running? Turning the steering wheel? Accelerating? Over bumpy roads?

If this noise is occuring whilst turning quite sharply it indicates the C.V Joint most of the time, when the rubber boot splits on the C.V joint the grease escapes causing wear on the joint, this is an easy enought fix to put and new boot/gater on and repack grease, but the noise will still be there 99% of the time because of the wear that has alrady occured. to get rid of the noise a new C.V joint will be required.

C.V Joint = Constant Velocity - Is commonly Located on drive shafts.
Boot / Gator = Rubber seal securing grease inside the joint.

i have a 1997 honda crv it makes a knocking noise when going over bumps is this normal the place where i bought it says its normal. thanks ron

Normal??? Have you ever heard a new car make the noise? Have it inspected at a tire and alignment shop. They'll check ball joints, tie rod ends, struts and upper mounts, and anti-sway bar links and bushings. Those links, and loose brake pads are the most common causes of noise over bumps. If a brake pad is loose or missing some anti-rattle hardware, the noise will stop when you hold light pressure on the brake pedal.