NorthStar Engine Ticking
 

I bought a used '07 Buick Lucerne on 08/30/15 with 59,606 miles on it. It has a North Star V-8. I did my first oil change three days ago at 65,000 using a synthetic blend oil. This morning after a thirty five minute drive to work I pulled in to the fast food drive thru and I noticed a very pronounced ticking sound. What might be causing this? Is this a problem indicative of the North Star V-8? Any thoughts? I love the car by the way. First V-8 I've owned since I bought my new '77 Firebird Formula back in '77.