Can someone help with this sound

[Stinger357]

About 3 weeks ago while driving my 97 ex 4.0L SOHC there seems to be a rattling/thumping sound coming from what I can tell from the rear of the vehicle. It only does it about evry 10 min but only lasts about 10 seconds. Also I noticed when I go over bumpy roads or a dip it almost always appears. Sounds kinda like a exhaust problem like something loose. Could it be my cat or my muffler? or my heat shield? It's kinda like a knocking sound but doesnt seem to be effected by speed. I can take off the accelerator and it still does it. When I hit the brakes it still does it also. its a rather fast rattling sound and like I said doesnt last but maybe 10 seconds. And sometimes I can drive 10 miles and not hear it at all? Well thats all the info I can provide. I will try to get a video of it so you can hear it from in the vehicle. It never does it in idle only while driving. Drivetrain issue?

 

[Peanut74]

Check your heat sheild that was my issue when I had a similar sound problem.

 

[Stinger357]

Is this something I can fix myself, and how do I "check" the heat shield and "what" is a heat shield and where is it located. Sorry newb to mechanical things. How much would a local mechanic charge to fix the problem, and what exactly is the problem has something come loose?

 

[Peanut74]

It is something you can fix yourself. The sheild is nothing more than an extra piece of metal between the muffler or catalitic converter and the bottom of the vehicle. It sole purpose is act as a heat barrier. With everything cool and truck blocked and get under the vehicle. When you find the heat shield just see if you can move it and touch the muffler or cat. It will move some but should not be so loose that it hits.

 

[Stinger357]

OK let's say I find the offending piece of metal how do I go about fixing it. Welding is not an option for me. I might just take it into the mechanic and see if he can fix it.

 

[Stinger357]

I've got my camcorder ready for a 10 mile trip today so I can record the rattling/knocking sound so you can hear it.

 

[wisneski7]

If its a heat shield it could be just a loose fastener. Not sure what size bolt but something a basic wrench could take care of. If you have a safe way to get the vehicle jacked up and jack stands under, you can just look at the whole exhaust system and check for any loose pipes (not likely) or the shield, which is a very thin piece of sheet metal that is secured above the exhaust pipe.

Also, my running boards seem to come loose every now and then and make an annoying rattle sound.

Aaron

 

[silentchris]

check the exhuast tip mine like to bounce around when i turn left and sound like the rear is going out