Engine noise after timing chain replacement

Someone I know just got a 1993 jeep with 2.5l and 100k miles on it. Soon as he got it home it had noise in front of engine. We replaced the timing chain/sprockets and tensioner. Tensioner looked worn out. We still need to
finish it up, but we started it to make sure the noise was gone. The timing noise is gone, but now there is a noise toward back top of engine, valves/lifter? This wasn't there before, did we get the timing off slightly installing the new timing set? This was our first time changing a timing set and we are pretty sure we kept everything lined up. Any ideas what to check?
Thanks

do a vacuum test.

A better discription would be we hear a tap or knock like sound. We'll check lines and engine vacuum when we get back too it.