Corsa timing chain advice?

i've got a Corsa 1.2 six 2001 (Y reg), i bought it back in Nov last year and it had a lil bit of a tappet noise when idling but sounded alrite when running when i bought it. Over the last few months the noise has got louder, its coming from the driver side of the engine so im guessing the timing chain is loose or the tensioner has stuck ? If it is do the chains break or can i get away with out changing anything for a while ? And will thicker oil dampen the noise ? I've already tried changing the oil and using engine flush but it didn't change