timing belt losing tension

[jason261270]

to anyone who read my request regarding possibile symtoms for my poor running at low revs, on my 2000 115pd passat.today a mechanic i know had a look at finding the fault ???.after checking turbo pipes the egr valve and other poss areas.he took the timing belt cover off to discover,about 50mm of slack in the timing belt!!.he could'nt believe the belt had not come off.bearing in mind i had the belt, tensioner and idler pulleys replaced around 5 months ago and covered approx 7000 miles since.he could not explain why this could be so slack,although he has'nt removed the tensioner for inspection.he said it 's possibile the belts jumped a couple of teeth throwing out the pump timing.which i suppose could explain the reason for poor running at idle.the cars back in the garage in the morning for further inspection.i wondered if anyone had heard of this problem before or is it just down to when the belt kit was fitted 5 months ago not been done correctly???????