Sticking valve/tappet?

[TeamSid]

My 2.1dj has developed a noticable tapping sound which sounds like a sticking tappet. This happened a while back but stopped when the engine warmed up. This time however, the tapping seems to be here to stay without some assistance. The van is sorned at the moment so it's run up and down the drive now and again....maybe not often enough. Any ideas on how to free off the offender with minimal fuss? Cheers.

[g60steve]

Very common fault on WBX's....a good 15 minute blast to get the tappet pressure back up should sort it.

[TeamSid]

Thanks Steve, I'll give it a bash.