2.Inspect overhead valve lash clearance: Insufficient clearance between the overhead valves and camshafts can cause tapping noises. For most Miata engines, the clearance is fixed using a shim-under-bucket design which rarely needs adjustment.
3.Check the exhaust system: A loose exhaust pipe or a damaged catalytic converter can also make a tapping noise. Visually inspect the system and look for any loose connections, holes or rust damage. Tightening any loose bolts or nuts can fix this.
4.Examine valve cover gaskets: Faulty valve cover gaskets can cause tapping sounds resulting from the engine's valvetrain. Check gaskets for cracks or leaks, and replace if needed.
5.Listen carefully: Try to pinpoint the source of the noise. Identifying where it's coming from can provide clues on whether the noise is from the lifter/rocker area or the camshaft/timing chain area.
6.Check the lifters/rockers: The hydraulic lifters and rockers may have issues or be excessively worn. Consider swapping around lifters or the entire set. Check for any sticking rocker arm or faulty valve.
7.Timing chain components: Worn timing components like the tensioner, chain, or guides, can also result in tapping noises. This may require removing the timing case cover to inspect and replace worn components.
8. Consult a mechanic: If the issue persists or you find it challenging to diagnose and repair, it's advisable to take your Miata to a qualified mechanic or automotive specialist for further inspection.
