If your vehicle is showing loud ticking or tapping noise from the top of the engine, here are the most likely causes and the parts you'll need to fix each one.
Low oil levels or heavily degraded oil prevents hydraulic valve lifters from fully pressurizing, leaving excess clearance in the valvetrain that causes a tapping noise.
A cracked exhaust manifold or blown gasket allows high-pressure exhaust gases to escape. This creates a sharp ticking sound that mimics a top-end engine noise, usually loudest when the engine is cold.
Hydraulic valve lifters can wear out or become permanently clogged with sludge over time. A collapsed lifter fails to maintain zero valve clearance, causing a persistent metallic tap.
If a spark plug is not properly torqued during installation, combustion gases can escape past the threads, creating a loud ticking or puffing noise from the cylinder head.
Fuel injectors naturally make a faint clicking sound as they open and close. A failing or worn injector can become excessively loud, mimicking a valvetrain tap.
Severe wear on the camshaft lobes increases the gap between the cam and the lifters. This results in a loud, rhythmic tapping that worsens with engine speed and requires major internal repair.