3.1L V6 (LG8) Features & Benefits
OVERVIEW
For the third consecutive year, the 3.1-liter, 60-degree LG8 V6 undergoes a series of improvements that improve economy and durability while keeping the engine current with increasingly stringent emissions standards.
NEW OR CHANGED FOR 2001 MODEL YEAR
* More Efficient Catalytic Converters
* Air Gap Downpipe
* Intake Valley Baffle
* Modified Lifter Guide
* More Durable Water Pump
* Improved Bearings for Accessory Drive Belt Tensioner and Idler
* High-Resistance Spark Plugs and Wires
* Plastic Fuel Tank
* Revised Throttle Body
* New Starter Motor
* Sleeveless Coolant Sensor
CUSTOMER BENEFITS
BETTER CATALYSTS
Improved technology increases the catalytic converter's efficiency, allowing National Low Emissions Vehicle (NLEV) certification with considerably less catalyst volume and lower cost. Improved production methods allow a new catalytic coating and thin-wall catalyst substrate--the source of the catalytic reaction that turns exhaust emissions to harmless vapor. These production techniques mean improved performance with less platinum, palladium and other precious metals in the converter. Converter volume has been reduced from 163 ci to 116 ci.
AIR GAP DOWNPIPE
An air gap downpipe connecting the exhaust manifolds with the catalytic converter, used on engines for California and select Northeast states for model year 2000, is applied to all LG8s. The pipe has dual walls separated by a jacket of air, and heats more quickly than conventional single-wall steel pipe. Combined with more efficient catalysts and a new Denso oxygen sensor with a 6.6-watt heating element, the air gap downpipe speeds emissions light-off by as much as five seconds. As a result, most LG8s need no Air Injection Reaction (AIR) for National Low Emissions Vehicle (NLEV) certification. Eliminating the AIR system eliminates assembly parts and reduces cost.
VALLEY BAFFLE
A baffle in the intake manifold valley protects the manifold gaskets from direct contact with engine oil, reducing the likelihood that the gaskets can saturate with oil.
LIFTER GUIDE
Valve lifters are now pre-assembled with the lifter guide, removing a step from the engine assembly operation and improving efficiency. Further, each guide is fitted with a plastic shield that, with the new intake manifold valley baffle, virtually eliminates the possibility that manifold gaskets can be exposed to oil. This protection removes a potential leak source.
WATER PUMP ASSEMBLY
The seal on the water pump shaft is made of more durable hard carbon silicon carbide. Further, the pulley bearings are sealed. Together, the improvements extend the water pump's useful life and reduce the potential for leaks.
DRIVE BELT TENSIONER
Bearings in the accessory belt tensioner and idler, which maintain proper belt tension without adjustment, are now validated to 150,000 miles of service. The permanent lube in the bearing maintains its lubricating properties longer. Further, the bearing seal is improved to keep the lubricant in and water, dirt and other contaminants out.
IMPROVED PLUGS AND WIRES
New high-resistance spark plugs and wires virtually eliminate the possibility of radio interference. The plug wires are soldered rather than snap-fit at the connector inside the plug boot. Soldering improves reliability and decreases assembly errors by reducing the possibility that the plug wire can inadvertently be detached from the connector. Finally, the Delphi spark plugs have silicon coated platinum tips to reduce fouling and the likelihood of service over the 100,000-mile plug life. The coating is particularly useful during post-production marshalling, when cars are started frequently and run briefly, and reduces the likelihood of pre-delivery plug cleaning at dealerships.
FUEL TANK AND CANISTER
Pontiac Grand Prixs with LG8 engines are equipped with a plastic fuel tank for model year 2001. The 2001 Grand Prix is equipped with a new 2.1-liter evaporative canister for its On-Road Vapor Recovery (ORVR) system.
REVISED THROTTLE BODY
A new throttle body spring lightens accelerator pedal feel. A hole in the throttle blade has been eliminated, reducing the minimum airflow rate and allowing a lower engine idle
speed.
STARTER
The new starter motor, supplied by Delco Remy America, draws less amperage than the starter used for model year 2000, yet delivers the same cold cranking power. That means the same starting power with less drain on the battery. The new starter is also lighter and costs less to manufacture.
SLEEVELESS COOLANT SENSOR
LG8s for the Malibu are equipped with a new coolant temperature sensor. The sensor uses a plastic insulator to protect electrical leads inside the brass housing, rather than a rubber sleeve, and reduces the possibility of assembly rejection or shorting in operation.
CONTINUING FEATURES
In 2000, new Multec II fuel injectors improved fuel efficiency by making fuel delivery more precise, and reduced the likelihood of injector clogging. Fuel pressure was increased from 300 to 380 kPa for improved hot starting. A number of enhancements reduced internal engine friction, in turn reducing noise and improving fuel economy. Those included reduced friction piston rings, revised cam profiles and a new cam gear and drive chain. The 3100 was fitted with a high-flow intake manifold and cylinder heads developed for the LA1 3.4-liter V8.
The LG8 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. "It's one of our bread-and-butter V6s, and we consider it a good value--a workhorse. It meets customer expectations for a base V6 at a reasonable cost." --Mike Parise, Model Year Manager, 60-degree V6 engines.
LEADERSHIP
The 3100 V6 continues to deliver solid performance, durability and economy with low cost of ownership. "A complete safety package requires on-demand zip for passing, merging into traffic and accident avoidance." --ROAD & TRACK 1999 BUYER'S GUIDE
