Strange sound coming from exhaust?

[gluciano]

95 x 4.0l 2wd with an automatic.

I have this strange sound that I hear coming from what seems to be the exhaust.
This happens usually when it first started and while being warmed up and also happens at low rpm in gear or in park. The sound that I hear almost sounds like some sort of rubbing from the exhaust on a heat shield or some sort of metal to metal sound. The sound goes away after it reaches about 1100-1400 rpm or so. I wiggled the exhaust and it seems tight, also while it was making this noise I did it too and it did not help the noise. Really embarrassing and annoying to hear it.

Does anyone have any suggestions on what might cause this sound?

 

[n2epv]

I had a loose oxygen sensor (acually 2 loose) that made all sorts of low RPM racket. The wires kept them from unscrewing all the way and falling out. They are in the most difficult locations to get at!!! I spent some significant time underneath my Mounty wacking on things with a rubber hammer before I found it

If I had it to do over again, trace the wires back to the O2 sensors and wiggle them. I suspect that they were such a bear to replace that they were never tightened down enough.

 

[gluciano]

I'll check it out. I think I am going to make a youtube real quick so you all can hear what it sounds like.

 

[gluciano]

OK here's a vid of the sound. Please let me know what you think it can be.


http://www.youtube.com/watch?v=Qb0kh9Bcoes

 

[gluciano]

Anyone?

 

[gijoecam]

With something as loud as that, it should be VERY easy to diagnose. Have someone (not just anyone, but someone you trust with your life) do exactly what you did in the video. Chock the wheels with a LARGE object (landscaping blocks come to mind), set the parking brake, and lay underneath the vehicle while they make the truck make the noise.

Without being there, diagnosing it is going to be difficult. There are any number of sheet metal bits that can be rattling on it. I'd be focusing specifically on the heat shields on the catalytic converters, as well as the heat shield that clips to the side of the transmission on the passenger side. That can pop off the flange and will sit there and rattle on the exhaust pipes, but it almost can't fall out. (Mine gets knocked off every winter a couple times a season... I think the slush somehow gets up there and whacks it out of place).

If all else fails, take it to an exhaust shop, show them what it's doing, and see if they can help you find it. If there's a chance they can make a buck, they'll probably look at it for no charge. (Just be sure and have them SHOW you the problem!!)

Good luck!

 

[gluciano]

Thanks, I'll give another look at it again paying attention to those places mentioned. If all else fails I'll bring it to a shop.

 

[gluciano]

Update, I took it to Midas and they told me it's the muffler. They are replacing it for free since I bought the muffler there four months ago.

 

[hersheyhanover]

mine had the same problem, but for mine it was just a loose heat shield so i just cut the exhaust lol.

 

[a_leggio]

I have a 99 that sounds like it has a real bad leak...I took it to my local muffler shop and they said I needed a new muffler...so I think that justifies a Flowmaster Install!!