I need help. My car is making the weirdest noise from the back. It only comes after I have been driving on the freeway and come to an exit. After I completely stop about 3-5 seconds later I get a weird knocking noise that sounds like it is coming from the rear of the car. It last for 10-15 seconds then goes away. The car drives fine and only does it after the freeway. I can not replicate it unless on the freeway and stoping. In the last month or 2 I have replaced the motor mounts, transmission mounts, front drive shaft, and power steering pump and return hose. The car seemed to be driving find, but starting Monday of this week I get the noise in the morning when going to work and exiting the freeway. Does anyone have any idea what could be making this noise?? Could it be a fuel pump issue?

Any help is appreciated.

Thanks

 

Start with the stuff you can see. Check that your exhaust isn't loose, the rotoflex joint, and any play in the front or rear drive shafts. If you can stand outside the car while someone revs the engine and then stops, I would do that. From your description, it seems like there's something that doesnt like the transition from high to low RPM. I wouldn't trust your hearing on this one while you're sitting in the drivers seat; sound has a tendency to travel through the body of the vehicle in odd ways.