anybody? i am confused about the flex plate bolts. As you can see in the video, I took the inspection plate off and checked them. But this flex plate has a valley in it that the bolts sit in which increases the space between the bell housing and the bolt to about 1/2 inch. I keep hearing people saying that if the bolt is finger tight it will hit but I don't see how that is possible. Anyway, they are all tight so that is not it.

If it is a rod bearing, it would be loud all the time, right? Cold or warm and at all speeds? I can barely hear it at idle if I am under the car and can't hear it at all when cruising. But under initial acceleration, it is quite loud.

If it were a wrist pin, it would be loud on deceleration, right? not happening here. So, could it be a broken piston? There are no metal shavings in the oil.

Any help is greatly appreciated as this is my DD.

Thank you!

 

Ok, so I have removed all the plug wires one by one and none had any effect on the knock. The torque converter bolts are all tight. I have changed the oil again and the oil is very clean with no metal in it. Could this be a lifter? I took it to a mechanic yesterday and he was confused by it as well. At first, he said rod but since it is not consistant and the plug wires had no effect, he mentioned carbon knock. Has anybody had this? Will Seafoam work?

 

Seafoam throgh the intake should remove carbon. Never seen it make a 4.0 knock, but it did on some early 80s 258s.

 

Any idea what this knock might be? I am pulling the pan this weekend to check the rods. Could it be a lifter?