new timing chain....knocking noise

I just had my timing chain and water pump replaced on my 96 2.2L Cav. I'm now hearing a strange knocking noise on the front end passenger side. Oddly, the tapping comes in fours (tap...tap tap tap) followed by a silent pause before resuming. It's not constant....I can drive a few miles and hear nothing, but it then starts up again. It sounds louder in idle but perhaps that's because when I drive it's being drowned out.

It sounds like there could be a loose bolt somewhere. Does anyone have an idea what the problem might be? The car is running fine and not overheating.

Thanks in advance!

my boss asked me to help diagnosis his car,he has same problem,96 cavalier,just had new timeing chain a few weeks ago,now has a knock from passenger side.looking up engine now,it is 2.2l,we are going to take off valve cover and check to see if it's a stuck lifter or something fairly simple.his has gradually gotten louder,also when you take oil cap/dipstick out,it kinda shoots drops of oil out of tube.went to check PCV valve and it was jsut a tube sticking out of the valve cover?know more when we take off valve cover and he buys a book.ANY help would be appreciated,so i don't look like a total idiot.never even popped the hood on one of these.is it overhead valve or overhead cam?can handle that easily enough,been there.not sure if it's related,but his rear main seal is bad too.