Ok heres the issue, I have a 2002 Mustang Gt, when im driving it i here this annoying tick coming from the passenger side of the engine. Now I dont believe its a rocker arm b/c I had this problem in my old 97 mustang and this sound has a slightly different tone. The strange thing is when I park the car pop the hood I dont hear it, ive also let it roll down a hill to see if it was a problem with the steering of suspension and didnt hear anything. It only seems to happen when the engine is under load also sometimes the engine will drop down to 400 or 500 rpm when its idling like its going to stall and then recover so im thinking it might be a vacuum problem EGR, PCV or other wise. So Im wondering if anyone has any suggestions or theories about this, any help would be appreciated.

 

try searching it. topic has been discussed many times and welcome to the forums.