1996 JXi 2.5L V6 makes tapping noise coming from the passenger side of the motor. This occurs only at morning start-up or if the car was standing for more than 12 h. This disappears after a mile or so driving. Engine runs great. When I start up after few hours there is no tapping sound. It only happens after prolonged car at rest. Heads and valves were replaced about two years ago when the timing belt broke. It has only 135K original miles.
If anyone has any idea, please help.

 

It's almost impossible to diagnose a specific problem using someone's description of a sound over the internet. You'll be getting nothing but guesses. You might narrow it down a bit if you buy a mechanic's stethoscope and see if you can pinpoint the source. Failing that, you'll need to get somebody knowledgeable to listen to it on cold start. Even then there's still a guess factor. Chances are his guess might be a little better than someone's who is hundreds if not thousands of miles away.

 

Yeah, you right, thought someone might have had similar problem and could share their experience.