i dont know much about these engines..but i do know that some have a tensioner type thing in them and it can cause them to tick/tap a little if its bad or something...
^^^
its b/c the loss of pressure somewhere...

maybe they need adjustment?
dont really know what it is..im not a motor guy unless its a honda or acura!!>>
might be completely wrong to ....

just throwing things out there...bumping the thread up for ya.
good luck