Pontiac Repair: 99 sunfire gt engine noise, pontiac sunfire gt, small block chevy

Question
1999 pontiac sunfire gt with the 2.4L auto trans.  i began noticing an odd tapping on the way home from work the other day that sounded like a heavy valve pinging/tapping.  my engine never had valve pinging/tapping prior and it has only 70K miles on it.  by the time i got home, 22 miles later, the tapping/pinging sound was constant and louder.  i know my fair share with auto mechanics and have done plenty of engine work in the past.  i was thinking a have a frozen lifter, at least that is what i am hoping to find.  this ping/tapping sounds like one lifter or valve that is bad, not multiple ones.  just wanted to get your take on this issue.  any advice would be appreciated.

Answer
Hey Adam:

Sounds like you have a handle on it. It is more than likely a lifter gone bad. The problem it it's really hard to get them out and also it's hard to pin point which one it is. seeing that this engine has 16 of them. The lifters are very different looking than that of one say from a small block chevy where when you have it in your hand you can see where it's collapsed. These don't look that way.  you can use a screwdriver and hold it along the cam carriers and try to listen to the handle end of the screw driver to try to narrow it down. I would also check the oil pressure in this engine if it's one or more lifters towards the back of the engine they are the last ones to get oil pressure. If the noise in towards the front of the engine it could be a timing chain issue. These engines are noted for chain issues and that that is a more likely source for the noise. The tensioners have a tendency to break or the chain guides break as well particularly the one at the top of the housing in between the 2 cams. Hope that helps you out a bit? Good luck!