Altima L4-2.5L (QR25DE) Hybrid (2007)
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If the added engine oil improves the compression, the piston rings may be worn or damaged. Check the piston rings and replace if necessary.
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If the compression pressure remains at low level despite the addition of engine oil, the valves may be malfunctioning. Check the valves for
damage. Replace the valve or valve seat accordingly.
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If two adjacent cylinders have respectively low compression pressure and their compression remains low even after the addition of engine oil,
the head gasket is leaking. In such a case, replace the cylinder head gasket.
9. Install spark plug, ignition coil, fuel pump fuse and harness connectors.