Faulty Hydraulic Tappet?

[Dubstar]

I think I have a faulty hydraulic tappet - 2ltr CU - and was wondering if there is a way of telling if it is or not? Do I have to remove it, and if I do, how can I tell if it's toast? I adjusted the clearances yesterday and it looked like the push rod tube had fallen out of its seat in the tappet, the engine is still lumpy and when I take off the spark plug lead it makes no difference to the idling. Oh, and the plug was caked in burnt oil and it still sounds like a bag of spanners!

[Dubstar]

Just went out and adjusted the tappets on the rh bank, and I could actually push one of the pushrods and compress the tappet with finger power alone, and not much finger power either - does this mean the tappet is dead?

[VWCamperfan]

It could mean that but there is an amount of movement due to spring loading in the hydraulic lifter. Adjust as usual and take it for a run to reduce tapping (or get rid of it if your'e lucky!), then check again when you should have more pressure in them. It will be easier to adjust this way. If you find one or more of them still presses in further than the others then it could mean those lifters have a problem. The design of them if very simple so probaby just a strip down and rebuild of tappet is all that's needed but replace if not confident doing this or don't like getting your hands dirty!