The 3.1-liter V6 GM LG8 (also known as the 3100) was built in the USA and Mexico from 1999 to 2004 for the Buick Century, Chevrolet Lumina, Chevrolet Malibu and Pontiac Grand Prix. It is an updated version of the L82 from the 60-degree V6 family, with pushrod valvetrain and 170-175 hp.
Specifications
| Production years | 1999-2004 |
| Displacement, cc | 3135 |
| Fuel system | distributed injection |
| Power output, hp | 170 – 175 |
| Torque output, Nm | 258 – 264 |
| Cylinder block | cast iron V6 |
| Block head | aluminum 12v |
| Cylinder bore, mm | 89 |
| Piston stroke, mm | 84 |
| Compression ratio | 9.6 |
| Features | OHV |
| Timing drive | chain |
| Phase regulator | no |
| Turbocharging | no |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 4.3 |
| Fuel type | petrol |
| Fuel consumption, L/100 km (for Buick Century 2001) — city — highway — combined |
13.9 8.7 11.7 |
| Engine lifespan, km | ~300 000 |
| Weight, kg | 188 |
The engine was installed on:
- Buick Century 6 (W-body) in 1999 – 2004;
- Chevrolet Lumina 2 (W-body) in 1999 – 2001;
- Chevrolet Malibu 5 (GMX130) in 1999 – 2003;
- Pontiac Grand Prix 7 (W-body) in 1999 – 2003.
Disadvantages of the GM LG8 engine
- The best-known weakness of this V6 family is the intake manifold gasket: it starts leaking coolant, which leads to overheating;
- Cracked vacuum lines often cause air leaks;
- The timing chain is durable and usually needs replacing only after 250,000 km;
- Owners also complain about ignition components and the fuel pump.
Frequently asked questions about the GM LG8
How much power does the GM LG8 make?
The GM LG8 develops 170 - 175 hp and 258 - 264 Nm of torque.
How much oil does the GM LG8 take and which one?
Engine oil capacity: 4.3 liters. Recommended oil: 5W-30.
Does the GM LG8 have a timing belt or chain?
The GM LG8 uses a timing chain.
Is the GM LG8 turbocharged?
No, the GM LG8 is naturally aspirated.
How long does the GM LG8 last?
The typical lifespan of the GM LG8 is ~300 000 km with proper maintenance.
What is the fuel consumption of the GM LG8?
Buick Century 2001: city 13.9, highway 8.7, combined 11.7 L/100 km.
What cars was the GM LG8 installed on?
Buick Century 6 (W-body) in 1999 - 2004; Chevrolet Lumina 2 (W-body) in 1999 - 2001; Chevrolet Malibu 5 (GMX130) in 1999 - 2003; Pontiac Grand Prix 7 (W-body) in 1999 - 2003.
What are the common problems of the GM LG8?
The best-known weakness of this V6 family is the intake manifold gasket: it starts leaking coolant, which leads to overheating. Cracked vacuum lines often cause air leaks. All known problems.
