Chevrolet Equinox Service Manual: Engine Component Description (LAF, LEA, or LUK)

Engine Description

Cylinder Block

The cylinder block is constructed of aluminum alloy byprecision sand-casting with 4 cast-in-place iron cylinder linersarranged in-line. The block has 5-crankshaft bearingswith the thrust bearing located on the second bearing from thefront of the engine. The cylinder block incorporates a bedplatedesign that forms an upper and lower crankcase. This designpromotes cylinder block rigidity and reduced noise andvibration.

Crankshaft

The crankshaft is cast nodular iron with8-counterweights. The number 8-counterweightis also the ignition system reluctor wheel. The main bearingjournals are cross-drilled, and the upper bearings are grooved. Thecrankshaft has a slip fit balance shaft drove sprocket. Number2-main bearing is the thrust bearing. The crankshaftbalancer is used to control torsional vibration.

Connecting Rod and Piston

The connecting rods are powdered metal. The connecting rodincorporates the floating piston pin. The pistons are castaluminum. The piston rings are of a low tension type to reducefriction. The top compression ring is ductile iron with amolybdenum facing and phosphate coated sides. The secondcompression ring is gray iron. The oil ring is a 3-piece springconstruction with chromium plating.

Oil Pan

The oil pan is die cast aluminum. The oil pan includes anattachment to the transmission to provide additional structuralsupport.

Balance Shaft Assembly

There are 2-block mounted balance shafts locatedon each side of the crankcase at the bottom of the cylinder bores.The balance shafts are driven by a single roller chain that alsodrives the water pump. The chain is tensioned by a hydraulictensioner that is supplied pressure by the engine oil pump. Thisdesign promotes the maximum effectiveness of the balance shaftsystem and reduces noise and vibration.

Cylinder Head

The cylinder head is a semi-permanent mold. Pressed-inpowdered metal valve guides and valve seat insets are used. Thefuel injection nozzle is located in the intake port. The cylinderhead incorporates camshaft journals and camshaft caps.

Valves

There are 2-intake and 2-exhaust valvesper cylinder. Rotators are used on all of the intake valves. Therotators are located at the bottom of the valve spring to reducevalve train reciprocating mass. Positive valve stem seals are usedon all valves.

Camshaft

Two camshafts are used, one for all intake valves, the otherfor all exhaust valves. The camshafts are cast iron.

Valve Lash Adjusters

The valve train uses a roller finger follower acted on by ahydraulic lash adjuster. The roller finger follower reducesfriction and noise.

Camshaft Cover

The camshaft cover has a steel crankcase ventilation bafflingincorporated. The camshaft cover has mounting locations for theignition system.

Camshaft Drive

A roller chain is used for camshaft drive. There is atensioner and active guide used on the slack side of the chain tocontrol chain motion and noise. The chain drive promotes long valvetrain life and low maintenance.

Intake and Exhaust Manifold

The intake manifold is made of composite plastic. The exhaustmanifold is cast iron. The intake manifold incorporates adistribution and control system for positive crankcase ventilation(PCV) gases. The exhaust manifold is a dual plane design thatpromotes good low end torque and performance.