Humming sound from muffler

[enzia35]

While driving in the low RPM's, I get this slight humming from the exhaust. Lasts about half a second or so. Any ideas on what it is? It's been raining lately, and it could be the water rapidly cooling off the pipes underneath, causing weird air pressure things to occur.

[ssms5411]

Re: Humming sound from muffler

Could be rear end making noise. But when the exhaust is hot it will expand and water hitting it will try and cool it, usually mine makes a popping sound after I turn it off and it sits, just the exhaust cooling down.

[venom3300]

Re: Humming sound from muffler

weld/clamp coming loose?

[pace2006]

Re: Humming sound from muffler

My stock muffler does this on low speed high load areas, such as going up the steep hill to my house. It only does it for a second or two every once in a while. To me, it sounds like something is vibrating or the muffler is moving around somewhat. But it doesn't happen often, so I'm not too worried about it. A new muffler will take care of it.

[Blizzard242]

Re: Humming sound from muffler

Another possibilities is that your exhaust is rubbing somewhere. During the lower rpms a different but more noticeable frequency is resonating from the pipes through the body that you can hear. Or you just plain have a leak somewhere.