sometimes i hear a weird sound coming from the back of my car when i accelerate it gets louder, it seems like it only happens when im driving at a certain place thats really windy like tall buildings or on a overpass thats pretty high. i was wondering if anyone else has experienced this.

sometimes i hear a weird sound coming from the back of my car when i accelerate it gets louder, it seems like it only happens when im driving at a certain place thats really windy like tall buildings or on a overpass thats pretty high. i was wondering if anyone else has experienced this.


Our 01' GMC Yukon used to have a flap in the rear wheel-well that would slap against the truck (sounded like a machine gun) when the wind would hit it just right. What year is your Escalade, because 02's and above don't have this little flap.

Our 01' GMC Yukon used to have a flap in the rear wheel-well that would slap against the truck (sounded like a machine gun) when the wind would hit it just right. What year is your Escalade, because 02's and above don't have this little flap.

i have a 03 and it does kinda sound like its something flapping, when i accelerate it sounds like its flapping even faster. like you said its like a machine gun.

Subject:
Exhaust/Muffler Heat Shield Rattle, Popping Noise Under Vehicle
(Install Heat Shield Retaining Straps On Muffler)

Models:
2002-2003 Cadillac Escalade, Escalade EXT
2000-2003 Chevrolet Silverado, Suburban
2002-2003 Chevrolet Avalanche
2000-2003 GMC Denali, Denali XL, Sierra, Yukon XL
2003 HUMMER H2
with 5.3L or 6.0L Gas Engine (VINS T, N, U - RPOS LM7, LQ9, L04)
Except 1500 Series Models

This bulletin is being revised to add RPO L04 to the Models information. Please discard Corporate Bulletin 02-06-05-005A (Section 06 - Engine/Propulsion System).

Condition

Some customers may comment on a rattle/popping noise from under the vehicle.

Cause

The separation of the muffler heat shield from the muffler may cause a rattle under the vehicle.

Correction

Install two heat shield retaining straps, P/N 15164621, to the muffler and muffler heat shield. Follow the service procedure below to correct this concern.
1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle (SI Document ID # 737171).

2. Install a retaining strap, P/N 15164621, around the front of the muffler and muffler heat shield as shown above.

3. Pull the retaining strap tight with one hand and tighten the Allen head screw with the other hand.

Tighten

Tighten the Allen head screw on the retaining strap to 13.5 Nm (119 lb in).

4. Repeat steps 2 and 3 on the rear of the muffler

5. Lower the vehicle.