Annoying exhaust rattle

[Lorne G.]

I am getting an annoying rattleing sound from the underside of my 67 big block side pipe car. The sound appears to be coming from the side pipes. I checked the sidepipe covers to make sure they are not banging against the sidepipes, and checked to make sure the sidepipes were not rubbing up against the frame.
I tapped the sidepipee with a hammer but no rattle was heard. The rattleing starts at 2000 rpm and continues upwards and is only evident under load. The rattling is not evident at idle regardless how many rpm's I rev it up to.
Can the rattle be caused by the inner shield or baffle inside the sidepipe even though it does not rattle when struck with hammer?

Any thoughts are appreciated.
Lorne

[Don H.]

Re: Annoying exhaust rattle

I chased down a rattle like you describe and it turned out to be worn out motor mounts. Don't know if that will apply in your case, but something to consider when all else seems to be good. good luck

[Lorne G.]

Re: Annoying exhaust rattle

Thanks for the suggesion Don. My motor mounts are new but actually I eliminated the metal V shaped spacer that was there initially so I am not sure if that would cause anything to rattle.
Lorne

[Ronald L.]

Re: Annoying exhaust rattle

Lorne - yes.

Even with new mounts, the engine moves under load and there is very little relative movement possible in that your exhaust and side pipes are one-with-the-engine. See if you make it go away by loosening the cover and screws and giving it a nudge forward and retightening. You might also find that the noise is from a loose front rocker panel to side pipe cover. I had that when I lost (broke) one of those original clips that go on the body, either part could be the culprit. The top rocker only attaches with a small screw/clip front a rear so a lot can happen in the middle.

If that fails to fix the issue, try and find a non flamable flexible thin material to slide up into the curve of the exhaust to side pipe cover and see if that makes it go away. I've had them contact there too. I would not necessarily leave it there though, jsut a tool to diagnose the source.

[Lorne G.]

Re: Annoying exhaust rattle

Thanks Ronald,
I will look at all the areas that you mentioned and try your recommendations.
Lorne