On the advice of a local guru, i checked my valvetrain for the umpteenth time to find this rattle. (if you remember my old topic).

Basically, id managed to put a different rocker in there, from a blue motor, in my red. Apparently they're slightly different? Anyhoo, one was clearly odd (way too shiney), so i searched my spares, found one that came from my set (right colour and wear marks) and hey presto, noise gone!

For about 1/2 an hour. Then it came back.

So, what valvetrain issue does this sound like? Constant mechanical tappey noise, but not your traditional "tap tap tap" of rocker slop. They all pump up, all stay pumped up, none are badly loose under the rocker bridges, and still, there's a loud, blatantly obvious noise from one of them.

Even my guru, who's done red motors his whole life, thinks it's a strange sound.

Yeah, its a red 202. All pushrods are flowing. Noise comes and goes.

Had the car dyno tuned today and it didnt make a sound. Drove it home, was fine for half the trip, rattled by the end.