Anyone else experiencing the same problem as me, with their roof popping, going down the highway with/out windows down? Sounds like its making popcorn.
My remedy is 3 possibilities...
A... Fill cavity between roof and headliner with stay foam
B.. Weld some flat stock atop the roof/inside between headliner..(my roof(S.C), did not come with a "bossed" roof
C... Install a sunroof 😊.
I'm leaning towards C. Anyone install one? I did one WAY BACK in the day with a s-10, but I didn't install it

 

I do not have any problems similar to how you would describe. Although, I have a super cab and normally have the back window slide open and the suicide doors windows flared as well as the two door windows.

 

Might try driving without the headliner in & have a helper try to locate the pop. I run into this pretty often on ductwork. We find the pop & take a hammer & dull screwdriver & reverse the pop, if that makes any sense,(it does work). Have u dropped anything on the roof recently or has it always done this ?

 

Check the cab mounts.

 

How about applying a big sheet of Dynamat to the inside of the roof metal?

 

Solve the problem first. I like remove the head liner and listen. Never heard of this problem before.

 

Guys... Whatever keeps it from popping, I'll give anything a gander.
. As for duration, it's been this way since day one..6.5yrs ago. The roof is so thin/light from sun exposure, it's about as rigid as foil. Just a slight push with finger, will make it pop/indent. I've tried the crack endures, suicide windows open, and nothing seems to work
. Didn't think of dynomat. May have to venture that route. Dug the sunroof, but one slam off piping or ladder upon the rack, and I'll have a permanent register for AC.

 

I had a similar problem on my 02. It ended up being the weather seal at the windshield. At higher speed it would flap against the roof and make the popcorn sound. Once I resealed it no sound.
You might want to check that first before removing the head liner.