Oil Consumption Diagnosis for GMC Truck GMC MD Steel Tilt (W Model) 2003
Excessive oil consumption (not due to leaks) is the use of
1.9 liters (2 quarts) of engine oil within 3 200 km
(2,000 mi). However, during initial engine break-in periods 4 828-6 437 km
(3,000-4,000 mi) oil consumption may exceed 1.9 liters
(2 quarts) or more. The causes of excessive oil consumption include
the following conditions:
| • | External oil leaks. Tighten the bolts and/or replace gaskets and
oil seals as necessary. |
| • | Incorrect oil level or improper reading of oil level indicator.
With the vehicle on a level surface, allow adequate drain down time and check
for the correct oil level. |
| • | Improper oil viscosity. Use recommended SAE viscosity for the
prevailing temperatures. |
| • | Continuous high speed driving and/or severe usage. |
| • | Crankcase ventilation system restrictions or malfunctioning components. |
| • | Valve guides and/or valve stem oil seals worn, damaged, or the
seal omitted. Ream the valve guides and install oversize service valves and/or
new valve stem oil seals. |
| • | Piston rings broken, improperly installed, worn, or not seated
properly. Allow adequate time for the piston rings to seat. Replace broken
or worn piston rings as necessary. |
| • | Piston improperly installed or miss-fitted. |
