Any Audi 80 8CB4 2.0 Gurus Out There?

[esseff]

I've got a 1992 Audi 80 8CB4 ABT engine 2.0L with 70,000 miles on the clock that is ruining my brain and bank balance. I had the cambelt and tensioner replaced when I bought it in 2014 and it gave me no trouble until about 3.5 years ago. When idling and hot, a loud grating chattering would appear from the general cambelt gear/tensioner area but would disappear when the revs were raised a little. Replaced the alternator on the advice of a backstreet mechanic but that did nothing. Eventually thought it was the tensioner pulley bearing so had it changed. Great, the noise went away for a couple of hundred miles and then it returned. Then another garage found the tensioner body had a hole chafed through it by the spring piston. That was changed, along with another pulley bearing assembly.
A few hundred miles later, guess what ... So another pulley from another supplier. Yeah, the noise came back so I had a Gates cambelt and tensioner pulley fitted last month. Silence was golden until this morning.
What the *#@%& can be causing it, nothing appears to be out of alignment. I want to sell the car but don't want to load the problem onto anyone further down the line. As a pensioner I can't afford to throw any more money at it in these troubled times.
Any ideas based on practical experience appreciated. I'm in the Derby area.

[Dr G]

Remote noise diagnosis is close to impossible, but if anyone will be familiar with the symptoms they'll be on Classic Audi. Their Facebook page is active and helpful.

[esseff]

Thanks, Doc,
I've been a member of Classic Audi for several years but for the past few months the website has been down whenever I visited. I checked it again after seeing your message and surprise, surprise - it's back again! :-)
I think I'll put my 80 up on its For Sale section, there'll be more than a few Audi-ophiles with a garage and spanner time to spare.
Cheers.