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Has anyone removed the headliner on a HTC? I stopped the roof retraction process about halfway, until I could access the headliner section. There are several push tabs/fasteners on the front and rear edge of the headliner, but I chewed up the first one and didn't want to do anymore damage. I used a metal panel tool but maybe I need to use a plastic tool. There are four tabs on the front edge and 5 tabs on the rear edge.
"Why?", you may ask. I am always looking for ways to quiet down the interior to make highway driving less stressful on the ears. You would be surprised how much noise in your ears causes body fatigue over time. If you knock on the headliner/roof it has a very tinny/hollow sound that could definitely use some thermal sound deadener. This would improve the sound quality and provide more insulation from heat.
I have already sound deadened the doors, as I do on all my vehicles, and not only does it quite down road noise, but it improves the sound quality of the speakers in the doors, especially the Bose subwoofers.
If there are any body/upholstery experts, I would love to hear your thoughts.
Popped the head off the fastener with a metal panel tool Maybe I'll try the plastic panel tool tomorrow. 4 fasteners on the front and 5 on the back of the headliner
By tapping on the roof panel and the headliner, there appears to be an air gap of about 2 - 5mm. Thermal sound deadener like Kilmat or other brands are 2mm thick, so I don't think there would be a fitment issue. If you have never used sound deadener, it is peel and stick and finish with a roller to promote adhesion. Kilmat has a foil outer layer that helps as an insulation, not only for the heat of the sun hitting the roof, but from engine heat when the top is fully retracted and the roof panel is tucked under the rear hatch. When applied to a surface like a car door, it changes the sound from a hollow echo to a "THUD". It is really quite impressive and actually works. It changes a noisy interior to Cadillac quiet. This helps when having a conversation with your passenger, phone call, or listening to music.
I wonder how much weight that would add to the top panel? It may bring in unwanted issues or stress to top motors or mechanism.
That is a good point! Here is what the specs say: Automotive self-adhesive insulation consists of butyl. KILMAT sound deadening has a total weight of 0.5 pounds/1 square feet. This weight ensures optimum efficiency and sound insulation that could be possibly gained from 80 mil thickness material. KILMAT 80 mil is light weighted sound deadening material.
At 0.5 pounds/1 square feet, two sheets of this stuff probably would not put a strain on the system.
By tapping on the roof panel and the headliner, there appears to be an air gap of about 2 - 5mm. Thermal sound deadener like Kilmat or other brands are 2mm thick, so I don't think there would be a fitment issue. If you have never used sound deadener, it is peel and stick and finish with a roller to promote adhesion. Kilmat has a foil outer layer that helps as an insulation, not only for the heat of the sun hitting the roof, but from engine heat when the top is fully retracted and the roof panel is tucked under the rear hatch. When applied to a surface like a car door, it changes the sound from a hollow echo to a "THUD". It is really quite impressive and actually works. It changes a noisy interior to Cadillac quiet. This helps when having a conversation with your passenger, phone call, or listening to music.
Were you able to remove the headliner efficiently with that plastic tool? I was trying to replace the camera that is mounted on that panel. It is easy to pop off with a plastic tool and get to the camera. After doing that I noticed I can't actually access the part of the wire to actually disconnect and be able to connect the new camera. I'm assuming the headliner has to be removed. When you removed the headliner, were you able to see the wiring/connector for that roof camera?
Were you able to remove the headliner efficiently with that plastic tool? I was trying to replace the camera that is mounted on that panel. It is easy to pop off with a plastic tool and get to the camera. After doing that I noticed I can't actually access the part of the wire to actually disconnect and be able to connect the new camera. I'm assuming the headliner has to be removed. When you removed the headliner, were you able to see the wiring/connector for that roof camera?
Removing the 9 push in fasteners was a pain in the butt and required me removing a few with pliers after the head broke off. Be patient, open the roof until the roof panel moves back about 12 inches from the front to gain access the 4 front fasteners and 5 rear fasteners, cover paint areas with towel, use a thin body panel tool to wiggle and pop out fasteners(not as easy as it sounds), and apply sound deadener to fit flat surfaces and use a roller or apply pressure to help adhere to the surface. You do not have to cover every surface to reap the sound deadening benefits, but try to cover at least 75%. Don't over think it. I have also gone a step further and deadened the doors for a very solid sound when you close the doors. This also helps clean up the droning Bose subwoofer for tighter base.
I only removed the roof headliner, not the section that houses the camera, so I didn't see any wiring for the camera.
Looks like at least six square feet total betweem the pixs, so around 3 pounds. I doubt that will over tax the HTC mechanism, but then again GM cheaped out on aspects of it, such as the metal cable being held into a plastic box rather than a metal one (with a plastic washer I think??).
Several users have reported that part faling in normal use. I've even seen posts using a zip tie to fix it. If it were a beefier system I doubt zip ties would be a solution.
So while 3 lbs of added weight ought to be fine, ya never know. Personally I never found the C8 HTC cabin particularly noisy, but to each his own. Props for doing the work yourself!
Did you take any sound readings before and after? What are the results. My experience with the HTC is not roof sounds but tire rumble which would need a different solution.
I did not take sound readings but you can search Youtube to see guys that do take sound readings; the results are impressive. I've been doing my cars for years and I mostly focus on the doors, floorboards and behind the seats. Audio installers will do this for your if you don't want to DIY. The improvements are cumulative and improve with each area addressed. Tire noise is a whole different subject and can be addressed by deadening the inner liner and quarter panels, which I did on my last C6. Switching to non-run flat tires is also a way to reduce tire noise. I hear Continentals are good.
Has anyone removed the headliner on a HTC? I stopped the roof retraction process about halfway, until I could access the headliner section. There are several push tabs/fasteners on the front and rear edge of the headliner, but I chewed up the first one and didn't want to do anymore damage. I used a metal panel tool but maybe I need to use a plastic tool. There are four tabs on the front edge and 5 tabs on the rear edge.
"Why?", you may ask. I am always looking for ways to quiet down the interior to make highway driving less stressful on the ears. You would be surprised how much noise in your ears causes body fatigue over time. If you knock on the headliner/roof it has a very tinny/hollow sound that could definitely use some thermal sound deadener. This would improve the sound quality and provide more insulation from heat.
I have already sound deadened the doors, as I do on all my vehicles, and not only does it quite down road noise, but it improves the sound quality of the speakers in the doors, especially the Bose subwoofers.
If there are any body/upholstery experts, I would love to hear your thoughts.
Popped the head off the fastener with a metal panel tool Maybe I'll try the plastic panel tool tomorrow. 4 fasteners on the front and 5 on the back of the headliner
I removed mine today and broke a few of the screws, the front side was no big deal, but the back side went into the roof, do you know of a way to get them out? I don't want to put the roof back on and hear them rolling around in there
If you gut the C8 interior and put peel and stick everywhere I’m sure it would be an amazing improvement if you want a quieter interior. I can’t imagine the htc roof makes any difference at all.
HTC headliner removal to add sound deadener
