El Viejo, It was long ago in a universe far away. I was driving home from Sonora to Oakland. Around Mantica it started making a lot of noise. When I pulled over and checked the engine it quit. Back on the highway it got noisy again. I slowed down to about 50 and went home. Around town it was fine if I didn't really get on it. When I got around to it I changed the lifters. It was a 235 I pulled from a '58 Chevy sedan. It was in a '49 pickup. I'm not recommending that you drive it because it could do a lot of damage to the cam and valve train. Like has been said yours could also be a weak or broken spring. Good luck, I hope it's an easy fix. Beater
