Compression Pressure Inspection

Allow the engine to warm up to normal operating temperature.

Using a 16mm plug wrench, remove the 4 spark plugs.

Fig 4: Identifying Spark Plugs

Courtesy of KIA MOTORS AMERICA, INC.

1. Insert a compression gauge into the spark plug hole.
   Fig 5: Checking Cylinder Compression Pressure Using Gauge

   Courtesy of KIA MOTORS AMERICA, INC.
2. Fully open the throttle.
3. While cranking the engine, measure the compression pressure.
   NOTE: Always use a fully charged battery to obtain engine speed of 200 rpm or more.
4. Repeat steps ( 1) through ( 3) for each cylinder.
   NOTE: This measurement must be done in as short a time as possible.

   Compression pressure: 

   1, 275 kPa (13.0 kgf/cm² , 185 psi)

   Minimum pressure: 

   1, 128 kPa (11.5 kgf/cm² , 164 psi)

   Difference between each cylinder: 

   100 kPa (1.0 kgf/cm² , 15 psi) or less

5. If the cylinder compression in 1 or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps ( 1) through ( 3) for cylinders with low compression.
   1. If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged.
   2. If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket.

Tightening torque: 

14.7 ~ 24.5 N.m (1.5 ~ 2.5 kgf.m, 10.8 ~ 18.1 lb-ft)

Tightening torque: 

9.8 ~ 11.8 N.m (1.0 ~ 1.2 kgf.m, 7.2 ~ 8.7 lb-ft)