Just baught 84 z28 with 305... before buying i noticed a tapping noise but one that sounded to be a simple thing... after driving 200 miles home i checked things out found all the driver side spark plugs to be very loose hand turn loose i figured that was the noise i was hearing( great yeah). nope it is definately drivers side 1 and 3 cylander area. can an exhaust gasket blow and make a noise that almost sounds like valve tapping??? i know i may be stretching that one but im wishing for something simple.. if i have the car in park and rev it, it doesn't or barely taps it only when under load that it taps.... any suggestions... ,

 

Could be an exhaust manifold gasket. they make a tapping sound when they blow.

 

either that or a loose rocker nut, if its still there after you change the gasket, take off the rocker covers and find the tap, tighten the rocker nut slightly until the tap goes away, should only take 1/8th of a turn, if that, so dont go crazy tightening them, do it cautiously, and good luck.

ps. if its still there after all that, you may have any number of bad things wrong in the bottom end of the motor.

 

Does it make the noise at idle? Did you try higher octane fuel?

 

You may find that there are no gaskets on the exhaust manifolds. Sometimes the factory never put them in there. It could also be a cracked exhaust manifold. It may be broke under the shield for the heat riser tube. Look around and see if there are any blackened areas from exhaust leaks

 

Thanks for the help noise is gone and i performed both process on the engine it runs a lot better too.