I dont think a timing chain would knock like that. I did the timing chain on mine thinking that was causing my knock. To narrow it down, take a long screw driver touch the timing chain cover and put your ear to it, then poke it around with engine running. Be careful. My problem was a bent oil pan hitting the crank. I was told many things, like I needed a new harmonic balancer and such. I just laughed when I did a general look and stethascope search and found out what my problem was. At first I thought it was my leaf-springs that where sagging, that caused me to replace 2 oil pans, cant afford the lift kit. In the end, motor mounts where to blame. Engine was sitting off to one side. And very low. This also caused my O2 sensor problem. When the engine sits off at an angle like that, the clutch linakage and oil pickup are offline. This caused a headache thinking it was my o2 sensor. But the Heep works again for me to break again
