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3100 3.1L (LG
Car Engine
2003 Model Year Summary
Revised Crankshaft Bearing
Revised Cylinder Heads
Revised Pushrods
Revised Camshaft Journal
Water Pump
Iridium Spark Plugs
Maximum Oil Change Interval Extended
Improved Starter Solenoid
FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES
REVISED CRANKSHAFT BEARING AND SEALS
The thrust bearing on the 3100 V6 (LG has been modified to optimize piston and bore oiling. The thrust bearing is fitted to the third main bearing cap to control the fore-aft movement of the crankshaft. The lower half of the bearing now has slots machined in a starburst pattern on its flange. Oil at the bearing cap is squeezed through the slots and forced in a fan pattern under the pistons and into the cylinder bore, providing another oil distribution path. This simple modification pays big dividends in improved internal lubrication and longer engine life.
REVISED CYLINDER HEADS
The 3100 cylinder head castings are tapped with 8-millimeter holes for the rocker arm bolts, reducing the tap size from 10 millimeter, and the rocker arms are secured with 8-millimeter bolts. This change commonizes machining for the 3.1L and 3.4L V6s (LA1) and increases assembly efficiency.
REVISED PUSHRODS
Pushrods in the 3.1L are no longer heat-treated. The pushrod guides are now made of low friction nylon, rather than steel, and the pushrods no longer need heat-treating to limit wear.
REVISED CAMSHAFT JOURNAL
The 3.1L front camshaft journal has been revised with a new timing pattern. This journal is now machined with 50/50 pattern of raised and lowered semi circles, rather than a single boss or lug. The operating principal for ignition and fuel injection timing has not changed, but the new timing pattern requires a slightly smaller cam sensor and modifications to the fuel injection wiring harness. The new timing pattern was introduced in anticipation of future development.
WATER PUMP
The 3100 water pump has a more efficient impeller design and the latest sealing technology, featuring a drip collector under the shaft. Most water pump seals are designed to release a few drops of coolant at a constant rate. With the drip collector, the drops are contained and evaporate. The drips are less likely to be mistaken for a leak.
IRIDIUM SPARK PLUGS
The 3.1L benefits from the latest spark plug technology. The new plug has an iridium core in the conductor and same internal resistance. Iridium helps maintain spark density over the life of the plug. The tip is still coated with platinum, and the plug maintains a recommended life of 100,000 miles, yet the electrode design improves combustion efficiency for maximum fuel economy and minimum emissions.
MAXIMUM OIL CHANGE INTERVAL EXTENDED
New calibrations in the Powertrain Control Module (PCM) extend the oil-change interval in all vehicles equipped with the 3.1L engine. Engineers have adjusted the Oil Life System to account for widespread use of the new GF-3 motor oil. GF-3 (for ΒGasoline Fueled, Standard 3ΒΒ) contains a friction modifier--an additive that makes the oil molecules more slippery. A new refining process leaves molecules in the base oil more stable. The oil degrades less with heat and retains proper lubricating properties longer.
Most oil change indicators work according to a predetermined mileage interval, which in turn is based on the oilΒs anticipated life under some generalized operating cycle. In the 3.1L, the PCM records a number of variables, including engine speed, temperature, load or rpm variance, and period of operation at any given load and temperature. With this information, the Oil Life System calculates oil degradation and recommends an oil change when the oil is near the end of its useful life--in other words, when an oil change is actually needed. With the 2003 revisions, maximum oil change intervals have been increased approximately 20 percent. There is no upward limit on the interval. The ownerΒs manual in cars equipped with the 3100 V6 will continue to recommend an oil change at least once a year.
The benefits of the unlimited mileage interval, measured by customer convenience, maintenance cost or environmental impact, are obvious. The customer should never pay for an unnecessary oil change again. Using oil for its true useful life results in less petroleum consumed and less used motor oil to be recycled or disposed of.
IMPROVED STARTER SOLENOID
The starter solenoid on all 3.1Ls has been improved to virtually eliminate the possibility of icing during cold-weather operation. Because of its typical location in most vehicles, the starter and its control solenoid can be exposed to moisture and ice during the winter. The solenoid's internal spool is now made of liquid crystal polymer (LCP), which does not absorb moisture. Further, the solenoid wire terminals have been redesigned in a tapered, round shape rather than a flat shape to reduce the possibility that moisture and ice can collect on them.
OVERVIEW
The 3.1L was developed as a V6, rather than a shortened V8. Its 60-degree cylinder-bank angle makes it inherently smoother than 90-degree V6 engines. In consecutive models years before 2003, the 3100 was extensively revised to improve economy and durability while keeping the engine current with increasingly stringent emissions standards.
With continuous improvement each year, the 3100 V6 continues to deliver solid performance, durability and economy with low cost of ownership.
Car Engine2003 Model Year Summary
Revised Crankshaft Bearing
Revised Cylinder Heads
Revised Pushrods
Revised Camshaft Journal
Water Pump
Iridium Spark Plugs
Maximum Oil Change Interval Extended
Improved Starter Solenoid
FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES
REVISED CRANKSHAFT BEARING AND SEALS
The thrust bearing on the 3100 V6 (LG
has been modified to optimize piston and bore oiling. The thrust bearing is fitted to the third main bearing cap to control the fore-aft movement of the crankshaft. The lower half of the bearing now has slots machined in a starburst pattern on its flange. Oil at the bearing cap is squeezed through the slots and forced in a fan pattern under the pistons and into the cylinder bore, providing another oil distribution path. This simple modification pays big dividends in improved internal lubrication and longer engine life. REVISED CYLINDER HEADS
The 3100 cylinder head castings are tapped with 8-millimeter holes for the rocker arm bolts, reducing the tap size from 10 millimeter, and the rocker arms are secured with 8-millimeter bolts. This change commonizes machining for the 3.1L and 3.4L V6s (LA1) and increases assembly efficiency.
REVISED PUSHRODS
Pushrods in the 3.1L are no longer heat-treated. The pushrod guides are now made of low friction nylon, rather than steel, and the pushrods no longer need heat-treating to limit wear.
REVISED CAMSHAFT JOURNAL
The 3.1L front camshaft journal has been revised with a new timing pattern. This journal is now machined with 50/50 pattern of raised and lowered semi circles, rather than a single boss or lug. The operating principal for ignition and fuel injection timing has not changed, but the new timing pattern requires a slightly smaller cam sensor and modifications to the fuel injection wiring harness. The new timing pattern was introduced in anticipation of future development.
WATER PUMP
The 3100 water pump has a more efficient impeller design and the latest sealing technology, featuring a drip collector under the shaft. Most water pump seals are designed to release a few drops of coolant at a constant rate. With the drip collector, the drops are contained and evaporate. The drips are less likely to be mistaken for a leak.
IRIDIUM SPARK PLUGS
The 3.1L benefits from the latest spark plug technology. The new plug has an iridium core in the conductor and same internal resistance. Iridium helps maintain spark density over the life of the plug. The tip is still coated with platinum, and the plug maintains a recommended life of 100,000 miles, yet the electrode design improves combustion efficiency for maximum fuel economy and minimum emissions.
MAXIMUM OIL CHANGE INTERVAL EXTENDED
New calibrations in the Powertrain Control Module (PCM) extend the oil-change interval in all vehicles equipped with the 3.1L engine. Engineers have adjusted the Oil Life System to account for widespread use of the new GF-3 motor oil. GF-3 (for ΒGasoline Fueled, Standard 3ΒΒ) contains a friction modifier--an additive that makes the oil molecules more slippery. A new refining process leaves molecules in the base oil more stable. The oil degrades less with heat and retains proper lubricating properties longer.
Most oil change indicators work according to a predetermined mileage interval, which in turn is based on the oilΒs anticipated life under some generalized operating cycle. In the 3.1L, the PCM records a number of variables, including engine speed, temperature, load or rpm variance, and period of operation at any given load and temperature. With this information, the Oil Life System calculates oil degradation and recommends an oil change when the oil is near the end of its useful life--in other words, when an oil change is actually needed. With the 2003 revisions, maximum oil change intervals have been increased approximately 20 percent. There is no upward limit on the interval. The ownerΒs manual in cars equipped with the 3100 V6 will continue to recommend an oil change at least once a year.
The benefits of the unlimited mileage interval, measured by customer convenience, maintenance cost or environmental impact, are obvious. The customer should never pay for an unnecessary oil change again. Using oil for its true useful life results in less petroleum consumed and less used motor oil to be recycled or disposed of.
IMPROVED STARTER SOLENOID
The starter solenoid on all 3.1Ls has been improved to virtually eliminate the possibility of icing during cold-weather operation. Because of its typical location in most vehicles, the starter and its control solenoid can be exposed to moisture and ice during the winter. The solenoid's internal spool is now made of liquid crystal polymer (LCP), which does not absorb moisture. Further, the solenoid wire terminals have been redesigned in a tapered, round shape rather than a flat shape to reduce the possibility that moisture and ice can collect on them.
OVERVIEW
The 3.1L was developed as a V6, rather than a shortened V8. Its 60-degree cylinder-bank angle makes it inherently smoother than 90-degree V6 engines. In consecutive models years before 2003, the 3100 was extensively revised to improve economy and durability while keeping the engine current with increasingly stringent emissions standards.
With continuous improvement each year, the 3100 V6 continues to deliver solid performance, durability and economy with low cost of ownership.