: Pinging Noise coming from Exhaust



bigksone
10-12-08, 11:19 PM
I have an 04 with 65k on it. lately I have been hearing a pinging noise coming from the exhaust system, right in the center of the truck. Performance seems a little sluggish also. Anybody have this before. Maybe my truck is trying to tell me to go get that corsa exhasut i've been eyeing:confused:

dstinson
10-12-08, 11:52 PM
its the heat shield, loosen the exhaust and cut it off (the shield not the exhaust)!! Once you loosend it you can rotate it down to cut the shield from the exhaust. I had the same thing happen (kinda embarrassing too). Or just get the Corsa exhaust, either way will fix.

ESCALADOR
10-13-08, 10:45 AM
Just go for the Corsa, you will not regret it! ;)

bigksone
10-13-08, 05:10 PM
its the heat shield, loosen the exhaust and cut it off (the shield not the exhaust)!! Once you loosend it you can rotate it down to cut the shield from the exhaust. I had the same thing happen (kinda embarrassing too). Or just get the Corsa exhaust, either way will fix.

Thanks - you're absolutely right. After you pointed me to the heat shield i started doing some more research and found this bulletin:

Popping/Snapping Noise When Vehicle is Hot, at Idle, or Immediately After Vehicle is Shut Off (Replace Muffler Heat Shield) #03-06-05-008C - (Oct 28, 2005)
Popping/Snapping Noise When Vehicle is Hot, at Idle, or Immediately After Vehicle is Shut Off (Replace Muffler Heat Shield)
2002-2005 Cadillac Escalade, Escalade EXT

2003-2005 Cadillac Escalade ESV

2002-2005 Chevrolet Avalanche, Suburban, Tahoe, Silverado, Silverado HD

2002-2005 GMC Yukon, Yukon Denali, Yukon Denali XL, Sierra, Sierra HD

2003-2005 HUMMER H2

with 4.8L, 5.3L, 6.0L , 8.1L Gasoline Engine (VINs N, U, T, V, Z, G -- RPOs LQ9, LQ4, LM7, LR4, L59, L18 )

This bulletin is being revised to include Pickup models, 8.1L engines and parts availability. Please discard Corporate Bulletin Number 03-06-05-008B (Section 06 -- Engine/Propulsion System).

Condition
Some customers may comment on a popping/snapping noise from underneath the vehicle at idle or immediately after the vehicle is shut off. Some popping/snapping noise from the exhaust system during cool down is a normal condition.

The noise may be intermittent depending on the outside temperature and or temperature of the exhaust system at the time of testing.

Cause
As the exhaust system warms and cools, the muffler and the muffler heat shield expand and contract at different rates and may cause a popping and/or snapping noise.

Some popping/snapping noise from the exhaust system during cool down is a normal condition. The customer should be made aware that this service procedure is designed to reduce but not eliminate all exhaust system popping and snapping during cool down.

Correction
DO THIS
DON'T DO THIS

Install a new heat shield and straps on the existing muffler.
DO NOT replace exhaust system components other than the muffler heat shield.


Follow the service procedure below to correct this condition.

Important: Some popping/snapping noise from the exhaust system during cool down is a normal condition. The customer should be made aware that this service procedure is designed to reduce but not eliminate all exhaust system popping and snapping during cool down.


Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information (SI Document ID #737171).
Caution:

In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges could result in serious personal injury.


Remove the nuts securing the muffler to the catalytic converter.
On 6.0L and 8.1L equipped vehicles only, loosen the exhaust pipe clamp.
Important: Do not use oil base lubricants on the rubber exhaust hangers.


Apply a soapy solution to the exhaust pipe hanger rods in order to ease the removal of the exhaust hangers.
Pry the exhaust hangers free from the exhaust pipe hanger rods.
Important: It is not necessary to remove the muffler from the vehicle to replace the muffler heat shield.


Reposition the muffler to gain access to the muffler heat shield.



Notice: Use extreme caution not to damage the muffler when removing the heat shield from the muffler.

Using an air-powered hack saw blade, or equivalent, cut off the existing muffler heat shield just as the heat shield rises off of the muffler. See the illustration above.
Remove the heat shield from the muffler.
Hammer flush the remaining heat shield to the muffler.



Important:

The new heat shield should not come in contact with the remaining muffler heat shield.

The new heat shield should not come in contact with the horizontal lock seam on the muffler.


Install the new heat shield (see parts list below) onto the muffler as shown above.



Install three straps, P/N 10391259, so that the strap screw head will be located on top of the muffler.

Tighten
Tighten the strap screw to 4 Nm (35 lb in).





Cut off the excess strap material and bend the strap over the strap screw head as indicated above.
Remove the exhaust pipe clamp.
Important: ONLY 6.0L and 8.1L equipped vehicles require a new exhaust pipe clamp, P/N 15103174.


On 6.0L and 8.1L equipped vehicles only, install a new exhaust pipe clamp, P/N 15103174, on the exhaust pipe.
Reposition the muffler in the correct position.
Slide the muffler forward into position, aligning the studs with the rear of the catalytic converter.
Install the nuts securing the muffler to the catalytic converter, but DO NOT tighten at this time.
Apply a soapy solution to the following areas in order to ease the installation of the hangers.
- The inner diameter of the exhaust pipe hanger

- The exhaust pipe hanger rod

Press the exhaust pipe hangers over the exhaust pipe hanger rods.

Tighten

Tighten the muffler nuts by hand until each contacts the metal flange.

Tighten the muffler nuts to 45 Nm (33 lb ft).

On 6.0L and 8.1L equipped vehicles only, tighten the exhaust clamp to 50 Nm (36 lb ft).

Lower the vehicle.

Now I just have to decide whether I'm going to fix it or get the Corsa.
I'll figure something out by this weekend.

dstinson
10-13-08, 05:27 PM
i said the same thing, but I did not have the cash lying around but I do have a die grinder so it was an easy choice for me.

Rolex
10-13-08, 05:49 PM
I had the heat shield issue on my 03. The dealer tried applying some kind of BS straps to quiet the issue. I had to bring it back to them a week later and have the entire factory exhaust replaced (under warranty) for $900.

If you're not under warranty I'd advise you to apply the $900 towards a Corsa exhaust.