Loud tick or knock from rear of car. Sounds like a midget is under my car with a hammer and every 2 sec he hits the frame with a hammer. But its doesn't happen all the time. It will even do it 2-3 times after the car is shut off. Car doesn't need to be moving. I have recently went to a straight shot glass pack. I have checked my clearances and everything looks fine. Its also doesn't do it every time I drive it. But when it does start it. it does it like clock work and is some what loud. I stuck it up on ramps the other day and the sucker would not do it. Then the next day off the ramps it did but I could not see anything. I wondered if maybe my heat shield is popping or maybe my fuel line is smacking the frame with fuel pump surges? I don't know but its strange. I swear someone is under there with a hammer.
Heat expansion Exhaust systems get much longer when they heat up and could be the problem. You may have clearance when it's cold, but goes away when they get hot and "grow". Look for rubbing evidence in the fore/aft direction.
Looking at your picture , I think I found your problem . Your dragging someone under the car and his Gym shoes are kicking the floor pans !:rant: Don't move the car , take a peek under there when the nieghbors aren't home ......ou: :eek2: :laugh: :3gears: :TU:
I would say it sound similar to an AC clickin on n off. Though I do not have AC in my trunk. It did it today and I was able to look but not pin point the source. I am thinking it is heat. How hot metal ping n pops. My pipes are weled and I used JB weld over the seams to cover any pin holes. I may have to stuff some insulation or something in n aorund the pipe to see if it helps. That or turn up the radio. But I really enjoy the new sound of my car / muffler. The single exit on the left is neat. Even neater is rattling the windows of slow people in the left lane as I pass them in the right. The sound did show up after adding the new exhaust.
