you are fine at 90,000miles but as soon as you hit 90,001 your car will self destruct if there is no maintenance done Since it is a used car that you bought from a stranger I assume, I would go ahead and either change the belt or inspect it. It should be really easy to get to the point where you can see your belt. I believe there are only to screws on the plastic cover on the very right of the engine (looking at the engine from front of car, drivers side). Your belt is under that cover. Look at the teeth and see if they are in good shape and fill the knotches on the wheel completely.