GM Service Manual Online
For 1990-2009 cars only

Inspection

Action

DEFINITION: Base engine misfire with coolant comsumption

Preliminary Inspection

Verify that there are no external coolant leaks. Refer to Loss of Coolant in Engine Cooling.

Isolate Affected Cylinders

    • Cylinder balance test with scan tool
    • Cooling system pressurization
    • Inspection of glow plugs
    • Compression test
    • Cylinder leakdown test

EGR System Inspection - if equipped

    • Inspect EGR valve and intake system for evidence of coolant leakage.
    • Replace the EGR cooler if any problem is found.

Injector Tube Leakage

    • Remove the injectors and injector tubes of affected cylinders.
    • Inspect for carbon tracking on the tapered seating surface of the cylinder head and the injector tube.
    • If evidence of injector tube leakage is found, inspect the tapered sealing surface on the cylinder head and the injector tube for improper machining or debris.
    • Clean debris and reassemble, or replace cylinder head or injector tube if necessary.

Cylinder Head Gasket Leakage

    • Remove cylinder heads of the affected cylinder bank and inspect for damage.
    • Replace components as necessary.

Cylinder Head or Engine Block Damage

    • Inspect the cylinder heads for cracks and warpage.
    • Inspect the cylinder block for damage.
    • Inspect the cylinder block to head mating surface for staightness.
    • Replace components as necessary.