Rattling noise troubleshooting

[jachez]

So I am having trouble diagnosing a sound my car is making while accelerating, it’s a metal rattling sound that happens when there’s more vibration from pushing on the gas.. 1st thought was loose exhaust clamp or heat shield but everything seems tight.. Speedo makes some noise but that’s a different sound. This noise is louder and comes and goes, usually after driven for a while. Any help appreciated. Can’t attach a video..

 

[BeepBeepRR]

Could it be spark knock? Timing issue? You can upload to youtube and post the link.

 

[jachez]

I do run premium fuel.. but it does happen more when it warms up.. where would I post the video? YouTube and tag forbbodiesonly?

 

[BeepBeepRR]

Youtube yes and copy the videos URL then click the media tab here in the chat when you are making a post and insert that URL.

 

[Geoff 2]

If it is coming from inside the engine, it is probably detonation.

 

[1967coronet]

If you rule out the engine.
I had a rattle i chased for some time , it ended up one of my flowmaster muffs had came apart inside.
Pretty easy to check once your onto it.
Slap each muffler with your hand.

 

[twecomm]

Could be drivetrain U joints.

 

[toolmanmike]

Probably loose flex plate bolts or a cracked flex plate.

 

[493 Mike]

Have you taken someone else with you? 4 ears are better than 2!
Mike

 

[turbine68rt]

Do you have the original heat riser setup on the passenger exhaust manifold?

 

[Moms68]

Does it make noise in neutral when revving the engine? If not, it's in the drive train, transmission/ clutch back.

Standard or auto trans? Does it make the noise when you shift into neutral or depress the clutch? If so, it's drive shaft back, wheel bearings or a loose part.

 

[jachez]

Have you taken someone else with you? 4 ears are better than 2!
Mike

Yes I have yesterday, have to wait two weeks to get it in the air at his shop.

 

[jachez]

Does it make noise in neutral when revving the engine? If not, it's in the drive train, transmission/ clutch back.

Standard or auto trans? Does it make the noise when you shift into neutral or depress the clutch? If so, it's drive shaft back, wheel bearings or a loose part.

 

[jachez]

No it does not make the noise in neutral while reving it, only it hear when moving, but not constant. It’s an automatic 727, 383 engine.

 

[jachez]

Do you have the original heat riser setup on the passenger exhaust manifold?

Yes I believe it does. Noticed that yesterday when I crawled under it.. wasn’t sure what it was for, just that it had a heat coil. Just searched about it now. Thank you! I did notice it’s kinda loose by hand, could possible rattle.

 

[jachez]

Probably loose flex plate bolts or a cracked flex plate.

I will check this. Thanks

 

[jachez]

If you rule out the engine.
I had a rattle i chased for some time , it ended up one of my flowmaster muffs had came apart inside.
Pretty easy to check once your onto it.
Slap each muffler with your hand.

Thank you I will try this

 

[jachez]

Do you have the original heat riser setup on the passenger exhaust manifold?

Now that I’ve researched this… I am thinking this is the issue.. it won’t be driven in the cold, so I think I can remove it if I can find a spacer to install in its place.

 

[68 Sport Satellite]

Sometimes a noise like this might only happen under engine/transmission load, even if it's not engine related.
I chased a rattle for years that would get louder with more throttle, but not in neutral. I finally found it while sliding out from under the car when I pulled sideways on the rear part of the exhaust. One of the metal tab exhaust standoff welds had broken. I could not see the break, but when I grabbed the exhaust and moved it side to side the metal weld break was very evident.

 

[68 Sport Satellite]

Now that I’ve researched this… I am thinking this is the issue.. it won’t be driven in the cold, so I think I can remove it if I can find a spacer to install in its place.

how to test if this is the issue?