YES ITS TRUE THERE IS A POSSIBILITY OF A COLLAPSED OR COLLAPSING LIFTER CAUSING THE PROBLEM, BUT LETS START WITH SOMETHING SIMPLE. THE SERVICE ADVISOR AT YOUR LOCAL DEALER MAY BE REFERRING TO THE TICKING SOUND OF THE ENGINES PURGE VALVE. WHICH DOES MAKE A TICKING NOISE UNDER NORMAL OPERATION. HOWEVER SOME HAVE OCCASIONALLY BEEN A BIT LOADER THAN OTHERS.