I need some input on identifying a loud tapping noise that’s coming from my motor. I would describe the noise as a tapping or loud clicking from center of the motor. It is very hard to identify the exact location. The tapping is intermittent and doesn’t happen constantly. The motor sputters and losses performance when the noise occurs. When the noise stops , the motor runs and sounds great. It happens weather the motor is warm or cold. My first guess was that one on the valves was out of adjustment and tapping or some debris was caught on a valve seat and the valve was pounding on it. I adjusted the valves and found nothing unusual. The valves were all tight in their seats with no side movement. My second guess would be the fuel pump but I can’t swear that the noise is coming from the pump.
It would seem that if the noise is coming from the valves, it would be a constant noise and would not come and go as it does.
Before I tear the head off and have a closer look , I would like some other suggestions on the cause of the noise.
Thanks very much for you help
