hdrolling
Member
Today while getting onto the interstate I WOT while merging and got up to about 90 mph and let up, then I heard a loud pop/thud in the rear under the car near the muffler area.
It wasn't a backfire but sounding more like I ran something over and it hit the underside of the car.
I didn't see anything in the road behind me so I didn't think much of it, later when I got off the exit I came to a stop. When I started going again I got up to 45 and when I let off it had a POP again, not as powerful as the first but you can feel and hear it in the rear. It did it a few more times on my way home and only while letting off the gas after accelerating.
Does this sound like unburn fuel igniting in the exhaust? I got underneath when I got home and don't see anything, made sure all the bolts to the GM performance exhaust were tight and that the flapper valve was still working.
Any thoughts? No engine noise at all or engine light, drives and pulls the same as always .
It wasn't a backfire but sounding more like I ran something over and it hit the underside of the car.
I didn't see anything in the road behind me so I didn't think much of it, later when I got off the exit I came to a stop. When I started going again I got up to 45 and when I let off it had a POP again, not as powerful as the first but you can feel and hear it in the rear. It did it a few more times on my way home and only while letting off the gas after accelerating.
Does this sound like unburn fuel igniting in the exhaust? I got underneath when I got home and don't see anything, made sure all the bolts to the GM performance exhaust were tight and that the flapper valve was still working.
Any thoughts? No engine noise at all or engine light, drives and pulls the same as always .
