Hitchcocks Forum

I've got a knocking noise that sounds pretty much exactly like this video: https://www.youtube.com/watch?v=B45wilMEkYU

Sounds to me like it's coming from the cylinder, and it's much louder at speed/possibly with higher revs. Anyone had this? It doesn't sound like what I've heard about pinging/pinking as it's not a rattle - it's a very regular rhythm in line with the revs.

"They all do that sir." Could be a slightly loose tappet clearance.

"They all do that sir." Could be a slightly loose tappet clearance.

Do the modern Bullets have hydraulic tappets? Sounds like a hydraulic tappet being starved of oil or leaking.

It's a 2000 model - I'm not sure if they're hydraulic but I want to say no - how can I know for sure? When I open up the tappet cover there's nothing that looks like hydraulics.

Apparently the hydraulic tappets are fitted to Unit Construction Engines.