Engine Cover GM Edge Red HTC Installed
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,507
Likes: 722
From: Sausalito CA
Engine Cover GM Edge Red HTC Installed
2023 HTC, Cover GM Part # 12697368
There are no instructions to install on an HTC.
For the list price of $495, which I bought with my GM points, instructions and the following parts should have been included:
A) Two additional bolts P # 11602424
B) Purge hose clip (rear of cover) P # 10317605
The part order photos made mention of 4 spacers P # 12683488, but I did not see a use for these.
I'll rate this as an easy 2 on a difficult scale of 10
1) Most important: Release the cooland tank for clearance.
Two 10 mm bolt heads, and be cognizant of a lower passenger side coolant tank support tang.
Wiggle the tank to tang, no lip, just a straight tang, the tank will come off.
There is a risk of scratching the cover if the tank is not placed aside, lifted out of the way.
2) The UTube makes mention of other's struggling with the tank's coolant hose "fir" tree.
No issue with the proper trim removal tool, the fir tree can be reused.
3) I placed rubber washers below the rear wiring brackets and under the bolt heads to prevent future scratches.
Torque for the bolts is 8 inch pounds, but a "good and tight" spec seems better.
4) Important: that rear clip ($7.10) for the purge hose is necessary.
I had to make one as this part seems too difficult for my local dealer to source.
5) Some microfiber towels used as protection as you lower the cover into position is prudent.
6) Install the bolts, noting some pressure may need to be applied to the cover's top to get the cover's mounting holes to align with the engine block holes.
In closing, no one will see this cover but me and a service department, yet I feel good knowing the Edge Red cover matches the Edge red valve cover.
The cover has sound/ heat insulation; whether that makes a material difference, I do not know.
I will place photos in "What did you do to your C8 today" thread soon.
Yes, I have also ordered a Custom Trim brand clear windowed engine bay cover, in Carbon Flash color.
As I wait for delivery, I purchased a weatherstrip to seal, rubber washers for the retaining screws, and some additional silver/ fiberglass self-adhesive heat reflective material to emulate the GM accessory windowed cover.
As for the debate of heat affecting the headliner or HTC top mechanisms, many seem to say no issue, but these cars are a maximum 5 years old; time will tell.
FWIW on my HTC, I have the Carbon Flash narcelles, and the underside of the roof body panel is also painted Carbon Flash.
Again, only me and my service department will see this, and I hope it "pops" with artistry.
Yes, again, I will place photos in the "C8 today" thread once completed.
There are no instructions to install on an HTC.
For the list price of $495, which I bought with my GM points, instructions and the following parts should have been included:
A) Two additional bolts P # 11602424
B) Purge hose clip (rear of cover) P # 10317605
The part order photos made mention of 4 spacers P # 12683488, but I did not see a use for these.
I'll rate this as an easy 2 on a difficult scale of 10
1) Most important: Release the cooland tank for clearance.
Two 10 mm bolt heads, and be cognizant of a lower passenger side coolant tank support tang.
Wiggle the tank to tang, no lip, just a straight tang, the tank will come off.
There is a risk of scratching the cover if the tank is not placed aside, lifted out of the way.
2) The UTube makes mention of other's struggling with the tank's coolant hose "fir" tree.
No issue with the proper trim removal tool, the fir tree can be reused.
3) I placed rubber washers below the rear wiring brackets and under the bolt heads to prevent future scratches.
Torque for the bolts is 8 inch pounds, but a "good and tight" spec seems better.
4) Important: that rear clip ($7.10) for the purge hose is necessary.
I had to make one as this part seems too difficult for my local dealer to source.
5) Some microfiber towels used as protection as you lower the cover into position is prudent.
6) Install the bolts, noting some pressure may need to be applied to the cover's top to get the cover's mounting holes to align with the engine block holes.
In closing, no one will see this cover but me and a service department, yet I feel good knowing the Edge Red cover matches the Edge red valve cover.
The cover has sound/ heat insulation; whether that makes a material difference, I do not know.
I will place photos in "What did you do to your C8 today" thread soon.
Yes, I have also ordered a Custom Trim brand clear windowed engine bay cover, in Carbon Flash color.
As I wait for delivery, I purchased a weatherstrip to seal, rubber washers for the retaining screws, and some additional silver/ fiberglass self-adhesive heat reflective material to emulate the GM accessory windowed cover.
As for the debate of heat affecting the headliner or HTC top mechanisms, many seem to say no issue, but these cars are a maximum 5 years old; time will tell.
FWIW on my HTC, I have the Carbon Flash narcelles, and the underside of the roof body panel is also painted Carbon Flash.
Again, only me and my service department will see this, and I hope it "pops" with artistry.
Yes, again, I will place photos in the "C8 today" thread once completed.
Instructor
Joined: Mar 2025
Posts: 218
Likes: 122
Wow, that’s a way more complicated installation than on a coupe. The hardest part on the coupe is figuring out how to release the front harness clips and then close them back afterwards. They can’t make a simple spring loaded clip…it’ has to be some newfangled clamp contraption that makes something so simple, that much harder.
