Big Time II wrote:
we do have brand new vent covers installed.
I had the same noise about two weeks after new vent covers were installed.
Turned out that one of the hold down clip pins on the vent cover wasn't installed properly, and only went through one of the holes in the cover. This allowed the vent cover to lift up about an inch when going more than twenty miles an hour.
The unlatched pin was scraping on the roof as the vent cover flapped.
I got a ladder, climbed up and pushed the pin through both holes and secured it properly. Now, no more noise.
You can see the clip pins in the video at https://youtu.be/w_w7mka-dHo?t=2m55s
Bill
Bill
