Engine Chevrolet B12S1

The 1.2-liter Chevrolet B12S1 or LY4 engine was produced in South Korea from 2002 to 2011 and was installed on many popular budget models of the concern, such as Aveo and Kalos. This power unit in a number of sources appears under a completely different index F12S3.

In 2002, a 1.2-liter engine was added to the Daewoo S-TEC engine series of gasoline units. It was the most common engine for its time with distributed fuel injection, a cast-iron cylinder block, an aluminum 8-valve head and a timing belt drive. To meet Euro 3 eco-standards, the manufacturer equipped this unit with an EGR valve. Hydraulic compensators are not provided here and every 30 thousand km the valve must be adjusted.

The B series includes engines: B10S1, B10D1, B12S1, B12D1, B12D2, B15D2.

The engine was installed on:

  • Chevrolet Aveo T200 in 2004 – 2008;
  • Chevrolet Aveo T250 in 2008 – 2011;
  • Daewoo Kalos T200 in 2002 – 2006.


Production years 2002-2011
Displacement, cc 1150
Fuel system distributed injection
Power output, hp 72
Torque output, Nm 104
Cylinder block cast iron R4
Block head aluminum 8v
Cylinder bore, mm 68.5
Piston stroke, mm 78
Compression ratio 9.3
Features no
Hydraulic lifters no
Timing drive belt
Phase regulator no
Turbocharging no
Recommended engine oil 5W-30
Engine oil capacity, liter 3.2
Fuel type petrol
Euro standards EURO 3
Fuel consumption, L/100 km (for Chevrolet Aveo T200 2006)
— city
— highway
— combined
Engine lifespan, km ~300 000
Weight, kg

Disadvantages of the B12S1 engine

  • The most famous problem of this unit is the too narrow oil channel jet that supplies lubricant to the block head. It quickly becomes clogged with deposits and the camshaft and rocker wear out from a lack of oil. You just need to drill it out.
  • Another weak point here is the crankcase ventilation valve. From wear, it can jam in the closed position, which will immediately lead to oil leaks, or it can in the open position, which will lead to air leakage and floating speed.
  • Owners of cars with such an engine often complain about failures of attachments: the starter fails, the thermostat sticks, the pump flows and the generator bearings buzz.
  • Even here, the ignition coil and its high-voltage wires serve for a relatively short time, the throttle servo teeth crumble and the fuel injectors clog.

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