Hi Everyone, I recently removed the front clip of my 72 Skylark for some body work and figured it a good time to do a good clean up on the motor and firewall. I covered my carb, and distributor with a plastic bag, and hit everything with a high pressure wash (avoiding electrical plugs etc as much as possible). Prior to the wash motor sounded great, after the wash I have a loud knock. It starts and idles like normal, knock seems to go away when engine is revved up. Any thoughts? 72 Skylark - 350 - 2bbl - points distributor Things I have checked: Oil looks good - not milky Oil pressure is good at 40psi There was moisture in the distributor cap - dried it out Did not see any water in points area in distributor. Checked all spark plug wires for water - there is none
Here is a link to a video of it knocking, then I accelerate the motor and let off and it knocks again. https://drive.google.com/file/d/1dRPG0nEJegn_Nu1yMSh25UJWFBeowC0e/view?usp=sharing
Sounds like a loose something external. Bracket, pulley, etc. As @12lives said, get a mechanics stethoscope or a long screwdriver and hold it up to your ear and start poking around... you'll find it pretty quick. https://www.amazon.com/Performance-...011&rps=1&sprefix=mechanics+st,aps,125&sr=8-6 $1o...
It's not an internal knock. It seems to go away when you Rev it up. You can try and remove one belt at a time and see when the noise goes away
Inspection cover is removed, so I ruled that out. Also confirmed all torque convertor bolts are tight and can not see any cracks in the flex plate.
I also confirmed that the flex plate gears all look good, and don't see that the starter gear is hanging up or anything.
Listen to the distributor cap. Had a knock that was coming from cap, loosened and reset cap. Didn’t even know I had touched cap before knock started.
Bingo. I've heard that noise before. Gulp! Check and see if crank pulley has any wobble to it. It will mess up the snout of the crankshaft quickly.
Actually fan is removed. I had fan, fan clutch and that pully off. Reinstalled pulley and fan clutch but not fan. No shroud installed as front end is pretty much disambled other than temporary mounted radiator to keep tranny fluid from spewing.
Interesting. I know things happen by coincidence but this thing sounded great prior to the wash. I will check the bolt and pulley. Thank you.
I went to change the blade on my lawnmower, which had always run/started flawlessly since new, & couldn't get the bolt off w/o an impact or wedging something in there & so left it for another day. Well, the grass needed cutting in the meantime & now mower won't start. I'm to the point that I think the sprocket on the cam slipped as the timing is definitely off & shear key is fully intact. Coincidence or something I did? Idk but hard to imagine what I did caused it.
Sounds like the rotating assembly is making contact with the oil pan. I certainly want to know what you find.
