It is actually the hydraulic valve lash adjusters (HLA) that is emitting the noise and not stuck valves if the diagnosis is correct. Such problems occurs when the HLA does not perform as required due to insufficient pressure and would intermittently.
Treatment might or might not resolve the problem depending on the extent of the fault with the HLA but that is the easiest way to go about and hope that it works. If that fails, you might have to service the HLA or replace faulty ones.
Monday, January 17th, 2011 AT 1:36 PM