M20 gurus help needed

[turbski]

[hasa]

Alternator? Waterpump? Video may distort the audio of course.

[turbski]

Alternator is disconnected for that video for troubleshooting.
inclined minds think alike lol

[turbski]

Sorry the other video had alternator un hooked. That one had it hooked up. Same result either way

[turbski]

I think I found the problem. In an earlier post I stated cam gear was loose. I pulled timing cover and set it aside.... never looked at it. Also found the lower timing cover loose.
I happened to bump the upper cover off my bench. It hit the ground face down and showed me the inside..... completely chewed up from the belt walking forward. Same with the lower cover..

[digger]

Yeah sounds more likely

[dvallis]

Yeah. I was going to say it sounded like something rubbing or grinding, not an engine knock.

We found the root cause of our timing belt wear. Two things: (1) extra thick head gasket 0.120" on the last build was putting too much tension on the belt, causing it to walk forward and rub on the aluminum cover (2) One bolt on distributor delete plate was too long, sticking out inside the cover. Belt was grinding against the belt. It's always something.

[turbski]

Just in case anyone has this problem in the future, yes the root cause was as mentioned. The timing belt walking forward caused the covers to smack one another making that awfull noise.
replaced the cam gear bolt, torqued and blue loctite . Re tensioned the belt by loosening the tensioner and rotating 2 full revolution then locking at 16 ft lbs. No more noise.
thanks for the sounding board guys!