hello we just purchased a 2000 discovery series 2 that had the engine replaced 2 months before my purchase.it sounded like a diesel idling i replaced exhaust gaskets twice,idler bearings,fan belt ,changed oil to rotella nothing stopped the noise .i then installed a set of lifters, it is as quiet as anything i have ever had.i have been a mechanic all of my adult life ,i would have sworn it was an exhaust leak. something to think about,i hope this helps.rconway

 

the only down side to that is you installed new lifters on an old cam shaft, so your noise will be back as soon as the camshaft eats up the new lifter. But it good for people to know not all noises are lower end.

 

Cams and lifters are made to wear down together. Imagine the crowned lifter in contact with the worn almost flat cam surface. And works the other way as well. Most cam makers want you to install new flat tappet lifters.

 

This is a great pic and great description. This lifter rotation is why when installing a new cam and new lifters they have the break in procedures. The new parts might fit a little tight and by running them at higher RPM than idle gives the lifters a good fighting chance of rotating every time the cam lobe comes up, until they are broken in a little. If you allowed the lifters to break in at idle, some of them might not rotate and then they'd wear out much faster.

EDIT: One of my engines sounds like a diesel too, but I'm not worried about it. ;-)

 

It is also a damn good reason to use the professional mechanic's visual inventory system, Mark VII. A slab of cardboard, with pieces poked thu it in order and labeled. If putting an engine back together, much better to keep lifters in same place they came from, rather than random mix up. Parts like these are worn down to a precise fit.