Compression Test
A noticeable lack of engine power, excessive oil consumption and/or poor fuel mileage
measured over an extended period are all indicators of internal engine wear. Worn piston
rings, scored or worn cylinder bores, blown head gaskets, sticking or burnt valves, and
worn valve seats are all p
ossible causes. A check of each cylinder’s compression will help
locate the problem.
Screw-in type compression gauge
1. Ensure that the engine is filled with oil to the proper level and with the appropriate
type (viscosity).
2. Ensure the battery is fully charged.
3. Warm-up the engine to normal operating temperature then shut off the engine.
4. Disable the fuel and ignition systems.
5. Label and disconnect all of the spark plug wires from the plugs.
6. Thoroughly clean the cylinder head area around the spark plug ports, and then
remove the spark plugs.
7. Open the throttle plate fully to the wide-open-throttle position.
8. Block the accelerator linkage open, or have an assistant fully depress the
accelerator pedal.
9. Install a screw-in type compression gauge into the No. 1 spark plug hole until the
fitting is snug.
10. Connect a remote starting switch to the starting circuit.
11. With the ignition switch in the OFF position, use the remote starting switch to crank
the engine through at least five compression strokes (approximately 5 seconds of
cranking) and record the highest reading on the gauge.
12. Repeat the test on each cylinder, cranking the engine approximately the same
number of compression strokes and/or time as the first.
Summary of Contents for TrailBlazer
Page 1: ......
Page 26: ...Fig 3 Typical body and undervehicle maintenance locations Refer to chart for descriptions ...
Page 29: ......
Page 30: ......
Page 31: ......
Page 175: ...Spring free length check Valve spring squareness check ...
Page 192: ...Front of piston mark ...
Page 361: ...5 3L Engine Except Saab Underhood Fuse Block 2003 2005 Early Production ...
Page 469: ...Removing the outer band from the CV boot Removing the inner band from the CV boot ...
Page 470: ...Removing the CV boot from the joint housing Clean the CV joint housing prior to removing boot ...
Page 471: ...Removing the CV joint housing assembly Removing the CV joint ...
Page 472: ...Inspecting the CV joint housing Removing the CV joint outer snap ring ...
Page 473: ...Checking the CV joint snap ring for wear CV joint snap ring typical ...
Page 474: ...Removing the CV joint assembly Removing the CV joint inner snap ring ...
Page 475: ...Installing the CV joint assembly typical ...
Page 553: ...9 Torque the lug nuts to specification 10 Lower the vehicle ...
Page 556: ...Toe in Frame Misalignment Frame misalignment ...
Page 588: ...Bleeding caliper ...
Page 624: ...Manifold gauge set components Refrigerant recovery recycling station ...
Page 676: ...A C Specifications ...
Page 677: ......