Cleaning and Inspection Procedure

WARNING: This page is about a different car, the 2004 Pontiac Sunfire and 2004 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: Use care when handling the crankshaft. Avoid damage to the bearing surfaces or the lobes of the crankshaft position reluctor ring. Damage to the teeth of the crankshaft position reluctor ring may effect OBD II system performance.

Clean the crankshaft with solvent.

Fig 1: View Of Crankshaft
Courtesy of GENERAL MOTORS CORP.
Thoroughly clean all oil passages and inspect for restrictions or burrs.
CAUTION: Refer to SAFETY GLASSES CAUTION in Cautions and Notices.
Dry the crankshaft with compressed air.
IMPORTANT: Reluctor ring teeth should not have imperfections on the rising or falling edges.
Imperfections of the reluctor ring teeth may effect OBD II system performance.
Perform a visual inspection of the crankshaft for damage.

Fig 2: Identifying Different Crankshaft Journal Wear Patterns
Courtesy of GENERAL MOTORS CORP.
Inspect the crankshaft journals for wear (1).
Journals should be smooth with no signs of scoring, wear, or damage.
Inspect the crankshaft journals for grooves or scoring (2).
Inspect the crankshaft journals for scratches or wear (3).
Inspect the crankshaft journals for pitting or imbedded bearing material (4).
Measure the crankshaft journals for out-of-round.

Fig 3: Measuring Crankshaft Journals
Courtesy of GENERAL MOTORS CORP.
Measure the crankshaft journals for taper.
Measure the crankshaft runout.
Using wooden V blocks, support the crankshaft on the front and rear journals.
Use the J 7872 in order to measure the crankshaft runout at the front and rear intermediate journals.

Fig 4: Measuring Crankshaft Runout
Courtesy of GENERAL MOTORS CORP.
Use the J 7872 in order to measure the runout of the crankshaft rear flange.
Replace the crankshaft if the measurements are not within specifications.
Inspect crankshaft bearings for craters or pockets. Flattened sections on the bearing halves also indicate fatigue.

Fig 5: Identifying Crankshaft Bearing Craters Or Pockets
Courtesy of GENERAL MOTORS CORP.
Inspect the crankshaft bearings for excessive scoring or discoloration.

Fig 6: Identifying Connecting Rod Bearing Scoring Or Discoloration
Courtesy of GENERAL MOTORS CORP.
Inspect the crankshaft bearings for dirt or debris imbedded into the bearing material.
Inspect the crankshaft bearings for improper seating indicated by bright, polished sections of the bearing.

Fig 7: Crankshaft Bearing Polished Sections (Improper Seating)
Courtesy of GENERAL MOTORS CORP.

If the lower half of the bearing is worn or damaged, both upper and lower halves should be replaced.

Generally, if the lower half is suitable for use, the upper half should also be suitable for use.