| Subject: | 2004 Grand Prix, Bonneville, LeSabre, Park Avenue, Impala with 3800 Engines
- Excessive Oil Consumption |
| Models: | 2004 Buick LeSabre, Park Avenue |
| 2004 Pontiac Bonneville, Grand Prix |
The following should be considered when diagnosing oil consumption complaints
of more than 1 qt in 2,000 miles. This information is based on powertrain observation,
analysis and findings of engines returned from the field for excessive oil consumption:
| • | Perform an oil consumption test as outlined in Corporate Service Bulletin
Number 01-06-01-011A. |
| • | Check the PCV system. Remove the PCV valve and verify that no components
are missing. Check all the O-rings for nicks or cuts. Replace any components that
are missing or damaged. Perform another oil consumption test IF any components were
found to be missing or damaged. |
| • | Perform a cylinder leak-down test using J 35667-A. Follow the
instructions provided with the tool and record leak-down of all cylinders. Leak-down
rates should be between 12-18%. Cylinders with 30% leakage or greater are considered
defective and will require service. |
| • | With all 6 spark plugs removed, note the coloration and condition of
the spark plug electrodes. Note any unusual coloration, electrode build-up or oil
on spark plug threads. Oil on plug threads generally indicates a valve seal/guide
issue. |
| • | Visually inspect the valve seals for proper installation. Improperly
installed valve seals can and will create an oil consumption issue. The intake valve
seals are colored blue (and have the letters "IN" molded into the top
of the seal) and exhaust valve seals are colored light green (and have the letters
"EX" molded into the top of the seal). Evaluation of engines
recently returned from the field for oil consumption concern revealed one consistent
concern of exhaust valve seals not fully seated. If the valve seal is detected to
be out of position, correct this condition by simply pushing down on the seal until
it seats properly. |
If further examination does not reveal the source of the oil consumption, please
follow normal procedures for Technical Assistance.
