Search the Community
Showing results for tags 'flapper valve'.
-
I have a 2017 GMC Siearra 1500 with the 5.3L & 8 speed transmission. There is a rattle noise that you can hear at cold start. I have seen posts on this issue and answers seem to be all over the place. When my truck sits overnight or while at work all day, there is a rattle that sounds to me like it is coming from the exhaust. I haven't gotten under the truck to see exactly where the sound is coming from. It typically lasts about 5-10 seconds. If you immediately put the truck in gear after startup the rattle goes away. Any info on exactly what this may be is appreciated. I have seen suggestions of torque converter, heat shield, hole in exhaust, flapper valve, and bad catalytic converter. Can anybody narrow this down to one of these issues?
- 4 replies
-
- cold start
- flapper valve
-
(and 2 more)
Tagged with:
-
I've read enough about these valves to want to clamp it in the full open position until I can delete it entirely when I get a cat-back exhaust. But, how in the hell do you clamp off the round ones on the 2018 trucks? Here's what mine looks like, and a simple hose clamp managed to slip off after only two days.
- 4 replies
-
- exhaust
- flapper valve
-
(and 2 more)
Tagged with: