| Item name | Spare part number | Description |
| 1 | - | Blow-by hose between right-hand camshaft cover and intake manifold |
| 2 | - | end cap |
| 3 | - | Right fuel rail |
| 4 | - | Left fuel injectors (3 pcs.) |
| 5 | - | Fuel supply line |
| 6 | - | Schrader valve |
| 7 | - | Right fuel injectors (3 pcs.) |
| 8 | - | Blow-by hose between left-hand camshaft cover and intake manifold |
| 9 | - | Crankcase ventilation valve with electrical heating |
| 10 | - | Camshaft position sensor (CMP) |
| 11 | - | Oil filler cap |
| 12 | - | Camshaft cover of the left row of cylinders |
| 13 | - | Oil line left valve lever |
| 14 | - | Camshaft bearing caps, left-hand cylinder bank |
| 15 | - | Left camshaft |
| 16 | - | valve lever |
| 17 | - | Sleeve |
| 18 | - | Valve spring plate |
| 19 | - | Hydraulic gap adjuster |
| 20 | - | valve spring |
| 21 | - | Valve stem seal |
| 22 | - | Left cylinder head |
| 23 | - | Left exhaust manifold gasket |
| 24 | - | valves |
| 25 | - | Cylinder head gasket |
| 26 | - | Plug/volume reduction valves |
| 27 | - | Timing chain tensioner |
| 28 | - | Right exhaust manifold gasket |
| 29 | - | Timing chain tensioner |
| 30 | - | Right cylinder head |
| 31 | - | Right camshaft |
| 32 | - | Caps of bearings of a camshaft of the right number of cylinders |
| 33 | - | Right valve arm oil line |
| 34 | - | Cover ka camshaft of the right number of cylinders |
| 35 | - | crankcase ventilation valve |
Cylinder heads
| Item name | Spare part number | Description |
| 1 | - | Right cylinder head |
| 2 | - | Left cylinder head |
The cylinder head with intake and exhaust ports on opposite sides has double valves and a central combustion chamber for spark plugs. The design of the intake ports provides swirl and control of the intake speed. This improves combustion and thus improves fuel economy, performance and reduces emissions.
The left and right cylinder heads are identical castings.
Camshafts
| Item name | Spare part number | Description |
| 1 | - | bearing cap |
| 2 | - | Camshaft |
One camshaft per cylinder bank is held by the camshaft housing; the hole for it is bored out in the cylinder head. The camshafts are fixed by a flange, which also controls the axial clearance.
The left camshaft contains a target disk, which, together with a crankshaft position sensor (CMP) provides determination of the position of the motor.
Valves and hydraulic lash adjusters
| Item name | Spare part number | Description |
| 1 | - | Valve stem seal |
| 2 | - | valve spring |
| 3 | - | Valve spring plate |
| 4 | - | Valve spring poppet key |
| 5 | - | valve lever |
| 6 | - | Hydraulic gap adjuster |
| 7 | - | Valve |
The valve springs are made of spring steel and are cylindrical in shape. The lower end of each spring rests on a spring cup flange that has an integral valve stem seal. The top end of the spring is held in place by the spring cap, which is secured to the top end of the valve stem by cone cotters. Tapered cotters have a series of grooves and lugs on the inside diameter that fit into the grooves and lugs in the tops of the valve stems.
Seats and valve guides are permanently seated in the cylinder head.
The valves are actuated by roller levers and hydraulic lash adjusters via camshaft lobes. When the camshaft cam presses on the top of the lever roller mechanism, the corresponding valve is lowered, opening the intake or exhaust port. This drive method reduces friction in the valve train.
The body of hydraulic lash adjusters contains a plunger and two chambers for supplying oil and pressurized oil. Pressurized oil is supplied to the lash adjusters through the main oil galleries in the cylinder head and through an opening on the side of the lash adjuster housing. Oil flows into the lash adjuster feed chamber and then into a separate pressure chamber through a one-way ball valve.
The flow of oil from the pressure chamber is determined by the gap between the outer housing and the central plunger of the gap adjuster. Oil is supplied to the top side of the plunger whenever the lash adjuster is moved. The downward force acting on the plunger forces a corresponding amount of oil into the lash adjuster housing. When the downward force from the camshaft and pushrod disappears (i.e. after the incoming side of the camshaft cam is passed), the oil pressure causes the lash adjuster plunger to rise again. This pressure is not enough to operate the valve effectively, but eliminates the gap between the pushrod and the top of the valve stem.
Valve lever oil line
| Item name | Spare part number | Description |
| 1 | - | Valve lever oil line |
The valve arm oil line is at the top of each camshaft and is attached with two bolts to the front and rear camshaft bearing caps. Oil is piped through the oil gallery in the cylinder head and distributed to the valve arms through adjacent spray holes in the pipe.
Cylinder head gasket
| Item name | Spare part number | Description |
| 1 | - | About laying of the left head of cylinders |
| 2 | - | Laying of the right head of cylinders |
The multi-layered steel cylinder head gasket has different coolant cuts for each cylinder, which ensures uniform flow of fluid.
Fuel injectors
| Item name | Spare part number | Description |
| 1 | - | fuel rail |
| 2 | - | Nozzle |
| 3 | - | Adapter |
Fuel injectors are installed in each of the two fuel rails, one for each cylinder head. The injectors and solenoid valves are controlled by the ECM. The atomizer of each nozzle is attached to the cylinder head by means of an adapter. The connection of each injector to the fuel rail is sealed with an O-ring. The injectors deliver fuel to the rear of the intake valves. For more information refer to Electronic Engine Controls (303-14A Electronic Engine Controls -4.0L)
Camshaft cover
| Item name | Spare part number | Description |
| 1 | - | crankcase ventilation valve |
| 2 | - | Camshaft cover of the right row of cylinders |
| 3 | - | Camshaft cover of the left row of cylinders |
| 4 | - | Oil filler cap and extension |
| 5 | - | Camshaft position sensor (SMR) |
| 6 | - | Crankcase ventilation valve with electrical heating |
The camshaft covers are made of thermoplastic. The left cover has a hole located directly above the camshaft timing plate for installing the crankshaft position sensor. Also, the left cover contains an oil filler hole.
Camshaft position sensor (SMR)
| Item name | Spare part number | Description |
| 1 | - | CMP sensor |
The CMP sensor is located at the front of the left-hand camshaft cover. The sensor is an electromagnetic sensor that generates a signal for the ECM containing information about the position of the camshaft. For more information refer to Electronic Engine Controls (303-14A Electronic Engine Controls - 4.0L)
The setting disk for the camshaft position sensor is installed in front of the camshaft of the left bank of cylinders. A flat machined surface near the front of both camshafts allows them to be locked when the valve timing is being adjusted.
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