'87 5ktqw problems persist

[JGB&MMB <gregnmeg@erols.com>]

I have an '87 5kcstqw w/120k with persisting problems. I hear a thunking
noise almost like the entire trans/engine is bouncing up and down 2-4
times when I release the accelerator abruptly especially in
1st, 2nd, 3rd or when shifting if I release the clutch very quickly.  If
I ease the clutch out I don't hear it.    My mechanic checked all the
engine mounts, claims all okay, and replaced some bushings which from
his
description sounded like they were at the back of the engine.  He said
he had to remove some panels(?) to see/check them and then replaced.
But I still have the thunking noises, maybe less pronounced though.
Initially, I got a response from said mechanic about parts
wearing/loosing up and with a quattro system to expect that kind of
noise.  I hate those kind of answers!

Related to this, I think, is a exhaust coupler/joint that keeps
loosening or snaps the bolts that hold it tight.  It looks like the
point where the header pipe joins to the rear section of the exhaust.
Kind of below driver and passenger feet.  My mechanic, again, has
replaced and retighted several times but problem keeps coming back.  I
think the bouncing engine/trans, is weakening the connection.

I've also been battling an A/C system that refuses to drain properly.
The mechanic and I both took turns trying to remove all the debris from
around condensor behind glove box.  Still sounds like water in fan
blades.  Occasionally I get spritzed w/water from the vents, usually
when turning corners but not always.  Sometimes it seems like just
turning the wheel makes the fan blades sound like they're hitting
water.  Another problem is that unless traveling at hiway speeds or
engine is cool, get very weak and damp feeling air.  Again mechanic has
checked and claims system appears okay, no leaks.  Checked freon
pressure and says it is okay too.  Very mysterious or incompetent
mechanic?

So there you have it, lots of questions.  All ideas suggestions are
greatly appreciated as I'd like to be rid of the prob's.

TIA,

Greg Butler
'87 5kcstqw
'74 VW Westphalia