L Series V6-3.0L VIN R (2004)
13. If adding oil increases the compression readings the piston rings are leaking.
Compression is low on the first stroke (first gage puff) and tends to build up on following strokes, but does not reach normal compression pressure.
The compression Improves considerably with oil. Inspect for worn or broken rings and piston ring land wear (pound out).
14. If adding oil does not increase the compression:
^
Valves or head gasket leaking: Compression is low on the first stroke. Compression does not tend to build up on the following strokes.
Compression does not improve with adding oil to the cylinder.
^
Head gasket: Two adjacent cylinders have lower than normal compression and adding oil to the cylinder does not improve compression.
Notice: Refer to Fastener Notice in Service Precautions.
