I have 99 mustang GT that has a valve lifter knock that seem's to go away when you rev the engine but is back at idle is less noticeable when the engine warms up. What will I have to do to fix this the engine is A 4.6 other then that it has lots of power. The mech. that put the engine in didn't seem to think it was a rod bearing as it would sound louder or could it be. The engine sat for at least 6 months before I put it in the car. The guy I bought it from said it ran fine before he removed it from his car. Is there an additive that I can try to treat the problem or what do I need to do.
May 21, 2010 at 8:59 PM