Hyundai Repair: 2000 Accent with 60,000 miles has low compression on # 3, piston rings, head gasket

Question
Is this a common problem with hyundais to have an early internal failure? It doesn't smoke, it only runs a bit rough and it sends a #3 misfiring code. Could it be rings or valves? But if rings, why only one cylinder?

Answer
This is an infrequent problem.  Most of the low compression issues I've seen are due to overheating.

To find out why the compression is low, you'll need to do a cylinder leakage test.  This involves applying compressed air to the cylinder while the valves are closed and then observing where the air exits.  Excessive air through the crankcase implies a ring problem.  Air mostly through the other cylinders indicates a head gasket or warpage issue.  Air mostly through the intake or exhaust indicates a valve sealing issue.

Each piston has piston rings.  So, if the problem were with the piston rings, something could have happened only on that one cylinder causing the ring problem.