67 Chevy pickup knocks after exhaust installed

[dano5083]

I just had exhaust put on my newly rebuilt 350 in my 67 pickup. When i ran it on open headers there was no knocking noise. Now that I have the exhaust on, it makes a knocking noise that gets louder and faster as I accelerate. What could be the cause for this?

[jhwkns]

Check your torque converter bolts.

[Frkypunk70]

You probably could'nt hear it before. My drive gears never bothered me until I got pipes installed out the back. Either that or the exhaust is hitting something now that you have one.

[Gene]

I'd say loose rocker arms, they can really be loud with a quiet exhaust.

[71swb4x4]

Two observations/ideas:
1) With uncorked headers, how would you know the knocking wasn't there? Seems to me the uncorked headers would make so much noise you wouldn't be able to hear the knock.
2) If it was truly caused by the new exhaust as your title implies, then I would check the exhaust first. An exhaust leak can sound like a knock to some people.

[Frkypunk70]

Originally Posted by 71swb4x4

Two observations/ideas:
1) With uncorked headers, how would you know the knocking wasn't there? Seems to me the uncorked headers would make so much noise you wouldn't be able to hear the knock.
2) If it was truly caused by the new exhaust as your title implies, then I would check the exhaust first. An exhaust leak can sound like a knock to some people.

Hey, wait a minute. Isnt that what I said.

[re1]

Maybe an exhaust leak ??