I have a 1998 1.8 se non turbo and had problems with the cam belt tensioner. Started off with a sort of rubbing rattling noise, which to me sounded like a heat deflector on the exhaust, so I did nothing about it until the car stopped one day and would not start.I then discovered the belt had been fouling on the cambelt housing, and the tensioner had failed causing the belt to go slack, jump a few teeth on the cog, and bend all 8 exhaust valves. The cambelt had been changed some 20000 miles earlier by a so called specialist, but the tensioner had not! Anyway over £900 later the car was back on the road. I have a receipt somewhere for all the parts and labour, I will try to dig this out and let you know the part number of the tensioner. Apparently this a common fault with the original tensioner fitted and has been upgraded by vw,as far as I know.
If I was you I would be very cautious about driving the car till you get the tensioner replaced.