I just picked up a '67 Delta 88 with a 1969 455. It has been sitting for 6 years. After sorting out the ignition it fired up and runs pretty smooth. It does have a clatter around #5 cylender. I'm going to pull the valve covers to check it out but want to see if the sound from this video is familiar to those out there with more experience.

 

Pulling the valve cover is a good start.

 

Are you running 10W30? If you go to 20W50 it should silence the clatter.

 

I doubt that

 

First thing you need to do is remove the oil filter and cut it open. Make sure it’s not full of metallic debris. Then start your exploratory surgery.

 

Man I hope so.

It sounds like an old diesel engine.

In any case Moldsmobile98 most prudent to go for simplest most cost effective possible solution first and work your way up. ( ie you want to tighten a battery cable before running out and buying a new battery...)

 

Thanks for all the input. I will update on findings.

 

Dry start from sitting could have burned up rocker pivot. Check filter for metal. Could be a spun bearing. Maybe why it was parked

 

I pulled the valve covers and with the engine running, no oil coming up through cylinder #1 exhaust valve. Collapsed lifter?

 

Collapsed lifter, bent pushrod, wiped cam lobe, plugged oil passage. Pull the intake and get a proper look at everything.