One problem related to engine knocking noise has been reported for the 1997 GEO Metro. The most recently reported issues are listed below.
The consumer slowed vehicle down from 65 mph and heard a knocking noise coming from under the hood. This caused the vehicle to stall. The consumer had taken the vehicle to the mechanic, and was informed that noise was coming from the engine. The mechanic then loosened o rings to stop the noise and stalling, but the noise and the stalling continued. The stalling occurred whenever the vehicle had to slow down or stop for any reason.