Now I have ticking noise after...

Now I hear a ticking noise coming from the right side of the valve cover. About 3 weeks ago my mechanic changed my timing chain, rails, tensioner, 5 belts and valve cover gaskets. It sounds like it's a lifter that's tapping. I have 156,996 miles on the clock. Has good power on the highway but stills blows out the blue puff of smoke leaving from a light.

1. Should I change the oil?
2. Is there anything that I can use to stop the ticking?

Please advise. Thanks.