#PIT5318C: Wind Buffeting Drone Type Noise And/Or Body Pressure Booming And/Or Water Leak – (Dec 21, 2015)- PIT5318A
|Subject:||Wind Buffeting Drone Type Noise And/Or Body Pressure Booming And/Or Water Leak|
|Models:||2015 Cadillac Escalade Models|
|2015 Chevrolet Suburban, Tahoe|
|2015 GMC Yukon Models|
|Vehicles Built Prior to 7/9/2015|
This PI was superseded to update Recommendation/Instructions. Please discard PIT5318B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Note: In some cases, correcting the roof bows may not eliminate the body pressure booming issue due to the fact that the roof is being excited by some other input(s).
These other areas will need to be addressed if the body pressure booming is still present at the completion of this. Examples of inputs that can excite the roof may be:
- Tires with excessive road force (Reference “condition 1” in the latest version of PI1354)
- Exhaust back pressure valve issues (Reference the latest version of PIT5404)
- Rear axle related issues such as pitchline runout (Reference “Other Sources of Vibrations” Step 3 in the latest version of “PI1354“)
Some owners may comment of a wind buffeting/drone noise or body/pressure booming (the feeling of pressure in the ears) while driving. The body booming issue may be more noticeable when the engine is in V4 mode for active fuel management (AFM). These concerns may be caused or amplified by the roof sheet metal no longer being attached fully to the roof bows (1).
On sunroof equipped truck, they may also notice a water leak from the headliner area. It may be found that the rear edge of the sunroof glass is considerably lower than the roof (2), even after performing a sunroof glass height adjustment. This is due to the roof sheet metal being detached from the roof bow directly behind the sunroof opening (3).
Correction for Condition 1
Remove the headliner to access the underside of the roof. Carefully inspect the front and rear sides of all 4 roof bows for insufficient bonding to the roof sheet metal (4). Press upward on the roof sheet metal to expose any separated sealer that may not be evident at first glance. Any roof bow that is not bonded to the sheet metal will need to be repaired. Note: The bonding does not have to contact the roof at the reinforcement ribs.
- Provide protection for the carpet and seats beneath the roof bows.
- Use mechanics wire, and a plastic scraper or similar tool to remove the old foam.
- Position a trim stick, thin side up-down in the reinforcement rib on either side of the middle roof sheet metal rib.
- Rotate the trim sticks from thin side to tall side up-down, as shown – this will create additional gap to allow for improved sealer application.
- Apply the panel vibration control material (as listed below), in an in-out / zig-zag pattern while working along, to fill the voids between the roof bow and sheet metal, on both the front and rear sides of the bow. In some cases, it may take a couple layers of material to fill the void.
- Rotate the trim sticks, from tall to thin side up-down and remove the trim sticks.
- Repeat process for remaining affected roof bows.
Correction for Condition 2
Repair for 1st bow on trucks equipped with a sunroof.
- Provide protection for the carpet and seats beneath the roof bow.
- Using mechanics wire, and a plastic scraper or similar tool, remove the old foam.
- Apply the panel control vibration material (listed below) along the top of the 1st roof bow, on both front and rear surfaces.
- Obtain two 2×4 pieces of wood long enough to span the opening of the sunroof. Wrap one of the 2×4’s with a cloth to protect the roof paint and place it on top of the roof, see Important Note below.
- Place the second 2×4 underneath the roof bow, sandwiching the roof sheet metal and roof bow between the two pieces of wood.
- Clamp everything together using three C-clamps as shown in the photo below (5 & 6). The clamps will need to stay in place until the panel control vibration material is dry.
Important: When placing the cloth wrapped 2×4 on the top/roof, pay close attention that it is far enough forward so that the 2×4’s rear edge does Not contact the roof’s raised reinforcement ribs. The roof ribs may be damaged/dented if the 2×4 is placed on them when clamped down.
|SEM 39977||*Panel Control Vibration Material||3 Tubes||1|
* For panel control vibration material ordering information, call SEM at 1-866-327-7829. SEM products are also available at local automotive paint supply stores.
For vehicles repaired under warranty use:
|Labor Operation||Description||Body Style||Labor Time|
|1480348*||Reapply Sealer To Roof Bows||Short Wheel Base||3.8 hr|
|Long Wheel Base||4.1 hr|
|Add||For Vehicles With Sunroofs||Short or Long Wheel
|* This is an unique labor operation for bulletin use only. This will not be published in the Labor Time Guide.|