89 sub exhaust............

I am needing some help with a noise. I have an '89 suburban with a 350 and a/c and about 183,000 miles. I have a loud clatter what seems like something is loose in the exhaust system. I recently replaced the exhaust system from the cat. back, but still have this problem. It seems to be more noticable at start up and lessens as the engine warms. It will be louder at idle speeds and dissapears when the RPM's increase. Now it will get conciderably louder when the A/C is turned on. Don't know where to look next, and any help will be appreciated.

If you dont have any loose clamps then it is the cat. The metal covering might be loose or the shield on the cat or the insides of the cat are loose

I will look at the shield, but I have a new cat. and exhaust system from there on........thanks for the reply.

Check the heat shileds around the exhaust manifolds. They could be loose.
-Ingoldx1

great...........I will check that out. Thanks for the reply.

if it helps any.....the sound sems to be comming from the left underside of the truck, and behind the engine..

If you mean the drivers side, check for play in the shift linkage. It could be shaking around. If you mean the passanger side, check the heat shield around the starter wires up on the back of the motor. You also should check out the tranny/transfer case mount for damage. Check out any clamps, fasteners, attachments while your under there.
Good luck!
- Ingoldx1 :p

thanks for the sugestions.........will check it as soon as I can get to it.