The 2001 Oldsmobile Alero came with two engine choices: a 2.4-liter in-line four-cylinder and an optional 3.4-liter V-6. The Alero shared many components, including engines, with the Chevrolet Malibu and Pontiac Grand Am as mid-size, front-wheel drive GMX130-platform passenger cars. Oldsmobile produced the Alero from 1999 to 2004. Common engine swaps included replacing the four-cylinder engine with the 3.4-liter V-6 or a 3.5-liter V-6.
Oldsmobile introduced the Alero in 1999 to replace the Achieva. The Alero came as a four-door sedan or two-door coupe with the base GX, mid-range GL and upscale GLS trim levels. The four-cylinder engine delivered an adequate 150 horsepower and 155 foot-pounds of torque, while the 3.4-liter V-6, which was an option on the GL and standard equipment on the GLS, produced 170 horsepower and 200 foot-pounds of torque. A four-speed automatic complemented the engines, although in 2001 an optional five-speed manual was available for the four-cylinder models.
The most common compatible engine for the 2001 Olds Alero is the LA1 3400 3.4-liter V-6 engine. This optional V-6 engine for Aleros usually is the alternative for Alero owners wishing to replace the 2.4-liter four-cylinder. The engine debuted in 1996, but owners installing this engine should use one from a post-2000 GM car to ensure the wiring harness and computer components are compatible. The 3.4-liter V-6 can be found in the 2000 and later Olds Silhouette, Pontiac Montana, Aztek and Grand Am, Chevrolet Impala, Venture and Monte Carlo, and Buick Rendezvous. The 2000 to 2002 V-6 engines had a tendency to leak from the lower intake manifold and need replacement. A major expense beyond the engine is to replace the existing transmission matching the four-cylinder with an Olds GMX130-platform V-6 compatible transmission. The engine bay that originally contained the four-cylinder can easily accommodate the 3.4-liter V-6. Any V-6 larger than 4 liters is not compatible and would require extensive modifications. Swappers should consider that the 3.4 V-6 from the Impala and Monte Carlo generate 10 more horsepower than the Alero’s V-6. The V-6 from the Venture, Aztek, Rendezvous and Silhouette produced 185 horsepower. The Grand Am GT’s version generated 175 horsepower, but the standard Grand Am’s output was identical to the Alero.
The General Motors 3100 series L82 3.1-liter V-6 is compatible with the 2001 Alero, but provides only a marginal improvement in overall performance, adding just 10 horsepower to the four-cylinder version with 185 foot-pounds of torque. This engine fits the Alero engine bay, although the wiring harness and computer components must be replaced because the engine came from pre-2000 Buick, Chevy, Olds and Pontiac models. An easier fit is the LG8 3.1-liter V-6 that began production in 2000 and generated 175 horsepower and 190 foot-pounds of torque. This engine is found in the 2000 and later Pontiac Grand Prix SE, Buick Century, and Chevy Lumina and Malibu.
General Motors' LX9 3500 3.5-liter V-6 is a relatively easy swap for the LA1 3.4- or LG8 3.1-liter V-6s. The 3.5-liter version debuted in the 2004 Chevrolet Malibu, and is quieter and runs more smoothly than any of the previous GM V-6 engines. It fits into an Alero, although a redesigned exhaust manifold requires some modification. Also required will be a wiring harness and powertrain control module. The engine develops up to 211 horsepower and 220 foot-pounds of torque. It originally powered the Buick Terraza, Chevy Uplander, Pontiac Montana, Saturn Relay, Chevy Malibu, Pontiac G6 and Buick Rendezvous.
