knocking 383

Alright I have a quick question. So I took my wagon out today and heard a knock so I suck my head under the hood. It sounded like it was coming from #1 so I pulled the plug wire and the noise got a lot louder. So layed under the car and put my ear on the oil pan and the noise was gone. I'm thinking it is valve train but would like a second opinion. Also the compression on #1 is down 40psi I would like to know if the two could be related. It also has a 383 if that matters. Thank you for all the help.

Pull the valvecover and check for a broken rocker arm. The pushrod tends to get pushed through the rocker tip and then it will make just such a noise as you mentioned.

Most wrist-pin or piston slap noises lessen when you pull the plugwire away.

The factory Mopar rockers are notorious for breaking.

Good luck.

I pulled the valve cover off and pulled the rockers they have some miles on them but they not broken just have normal wear.

start it up again, pull 1 wire at a time till you find the 1 that is knocking. Valve train is usually a clattering sign. Rod and wrist pin problems are a knocking sound. Either way you have a problem that most likely indicates a teardown is in your future.

Ok so I pluged the wires off one by one and the noise didn't change I also noticed that when the car is wramed up the noise is almost gone and gets alitte louder when you rev it. Thank for the help so far.

What's your oil pressure?

check your fuel pump push rod.

I'm going to check oil presser and the fuel pump push rod but what is the best to check the push rod, just put hand on the fuel pump.

NOT the lever on the pump,, the rod that pushes against it..

No reason to check fuel pump push rod if it were worn enough to make a noise you wouldn't have any fuel pressure either....

If it goes away when warmed up could be piston slap. If so run it.

Pulling one plug at a time didn't isolate it.

so next, remove the intake and exhaust pushrods for one cylinder at a time. see if you can narrow it down to valvetrain somewhere.

if you still can't find it, then it really doesn't mater what the noise is, because you need to pull the motor out and rebuild it.

I'm just going to mention this because I know two people who have done this, not really sure its your problem, but I know two people who both blew the ring lands out of #1 on a 383. Both left the bores undamaged, but they had be replace a piston.