got an Audi 80 sport 2.0 8v 1991 and took off the cambelt cover the other day to find a large mess of black bits of plastic and burnt looking rubber started the engine with the cam belt cover off and noticed that the tentioner was not spinning was wondering if this is ment to spin as it has a mass of congealed burnt black plastic around it

was wondering if anyone could give me some incite on to this

is it ment to be spinning and is it regular to have a mass of like black plastic crap all in the cam belt cover