1987 s4 - there is a persistent knocking from the back of my 928 that sounds like the tailgate is not properly shut, although it is. I have take out all the other possible bits (tool kit, spare tyre, jack, brace etc) and the battery - all to no avail. Any one had a similar problem - it's driving me nuts!
Thanks
Mark

 

Check your exhaust hangers.

Try shimming the side rubber bumpers for the hatch with little bicycle tire patches.

Check the 2 round rubber bumpers on each corner of the hatch.

Good luck.

 

Will do
Thanks

 

If you've got a bad exhaust hanger, the way to reinstall a new one is to UNBOLT THE METAL HANGER POINTS. Don't try to wrestle that rubber biscuit on. It's like trying to teach a pig to sing. You won't accomplish anything but to irritate the pig. Assemble the biscuit to the hangers off the car, then re-install them.

 

It's not the hanger - it's the back of what appears to be a badly corroded fule tank cradle which is flapping around. Wish I'd looked underneath earlier! Do these rot easily?
M

 

If its an end of the strap high up under the rear, sounds like it lost its bolt? Or has part of it really rusted out and broken? There are 4 arms going up high and bolting to the floor.
jp 83 Euro S AT 48k, BTDT