clicking noise 96 Range Rover 4.0

I have a clicking noise that starts about 1 min. after cold start. It occurs in neutral or park or drive. It seems to come from under the engine in the rear of engine. Oil change and adding mystery oil and heavier 10W40 oil makes no change. If I rev up engine it seems to go a little faster up to about 2k rpm then seems to disapear. At idle it's worse. Car has 130K miles but a new short block was installed in warrenty at about 35K to cure a "tappet noise" they couldn't find. The new short block seemed to eliminate most of the tappet noise. A used trans and torque converter was put in about 2K miles ago. This problem started about 500 miles ago. I was told by a mechanic that there is a "flapper" valve in the oil pickup line that will cause that and not to be concerned. We have checked under the car and it does not appear to be muffler or cat. converter.

It could be a hydraulic tappet, you will have to find where on the engine the noise is coming from. You can use a long screwdriver as a stethoscope and listen to various parts of the engine ( be careful is can be very noisy, also keep clear of the HT leads ) if you think it’s the tappets you can remove the rocker cover and see the rocker moving as the sound occurs. You now know the area and can check the moving parts.

Try reposting over in the Range Rover section.