Cylinder Heads
Cylinder Heads
Special tools, testers and auxiliary items required
• Adapter (T40058)
• Locking Pin (T40069)
• Camshaft Locator (T40133)
Removing
• Engine installed.
• The following information describes how to remove both cylinder heads at the same time.
• If only one cylinder head will be removed, follow the applicable instructions in the following description.
CAUTION!
There is a risk of injury because the fuel is under very high pressure.
• Before opening high pressure area of the fuel injection system, fuel pressure must be relieved to residual pressure.
- Reduce fuel pressure in high pressure area.
- Remove the front exhaust pipe and catalytic converter for the left pipe. Refer to => [ Left Front Exhaust Pipe with Catalytic Converter ] Left Front Exhaust Pipe with Catalytic Converter, and for the right pipe, refer to => [ Right Exhaust Pipe with Catalytic Converter ] Right Exhaust Pipe with Catalytic Converter.
- Remove ribbed belt. Refer to => [ Ribbed Belt ] Ribbed Belt.
- Remove the front coolant pipe. Refer to => [ Front Coolant Pipe ] Front Coolant Pipe.
- Remove the upper section of the intake manifold.
- Remove both intake manifold lower sections.
- Disconnect the electrical connectors on the fuel injectors.
- Remove the protective plate - 1 - for the high pressure line - arrows -.
CAUTION!
Risk of injury from fuel.
• To reduce residual pressure in fuel system, lay a clean cloth around the connector and carefully loosen connector.
- Remove the threaded connection - 1 -.
- Remove the bolts - arrows - on the retaining plates and the high pressure line.
• Ignore - 2 and 3 -.
- Remove the threaded connection - 2 - and move the fuel supply line to the side.
- Disconnect electrical connectors - 1 - and - 6 -.
• Ignore - 3, 4 and 5 - and - arrows -.
- Disconnect the right and left electrical connectors - arrows - on the camshaft adjuster actuators.
- Remove the bolts - 1 - and - 2 - and free up the electrical wiring harness.
- Remove the cylinder head cover. Refer to => [ Left Cylinder Head Cover ] Left Cylinder Head Cover or => [ Right Cylinder Head Cover ] Right Cylinder Head Cover.
- Disconnect the electrical connectors on the left cylinder head:
1 Camshaft Position (CMP) Sensor 2 (G163)
3 Camshaft Adjustment Valve 2 (N208) and Camshaft Adjustment Valve 2 (exhaust) (N319)
4 Camshaft Position (CMP) Sensor 4 (G301)
• Ignore - 2 - and - arrows -.
- Move the electrical wiring harness to the side.
- Disconnect the electrical connectors on the right cylinder head:
1. Camshaft Adjustment Valve 1 (N205) and Camshaft Adjustment Valve 1 (Exhaust) (N318)
2. Engine Coolant Temperature (ECT) Sensor (G62)
3. Camshaft Position Sensor (G40)
4. Camshaft Position (CMP) Sensor 3 (G300)
- Move the electrical wiring harness to the side.
- Remove the left and right timing chain covers. Refer to => [ Left and Right Timing Chain Covers ] Left and Right Timing Chain Covers.
- Remove the bolt - arrow - and remove the oil dipstick with the guide tube.
- Remove the vacuum hose from the vacuum pump - arrow - and free it up.
- Remove the bolts - arrows - on the rear of the cylinder head.
• Left cylinder head: 3 bolts.
• Right cylinder head: 4 bolts.
• The cams on the intake camshaft partially restrict access to the cylinder head bolts, such as bolts - 1 - and - 2 - shown in this example.
• The slider on the camshaft must be pressed in the direction of - arrow A - using a plastic wedge to remove the bolt - 1 -.
• The slider on the camshaft must be pressed in the direction of - arrow B - using a plastic wedge to remove the bolt - 2 -.
CAUTION!
Risk of damage.
• The camshaft slider must only slide in the base-circle phase, that is the rocker arm on the slider that will be moved must not be loaded with a cam. When loosening the cylinder head bolts, follow the sequence described in the following instruction.
There is a risk it could break.
• The camshaft sliders must not slide on the thin ribs.
- Insert the (T40058) guide pins as follows:
• The large diameter - arrow 1 - faces the engine.
• Small diameter - arrow 2 - points to adapter.
- Rotate the crankshaft in the direction of engine rotation - arrow - using the (T40058) until the camshaft position shown in the following illustration is reached.
• The openings - arrows - on the exhaust camshafts must face toward the outer side of the engine as shown in the illustration.
Left cylinder head:
- Slide the unloaded camshaft slider - B - as far as the stop in direction of - arrow -.
Right cylinder head:
- Slide the unloaded camshaft slider - F - as far as the stop in direction of - arrow -.
Continuation for both cylinder heads:
- Turn the crankshaft one full revolution (360°) in the direction of engine rotation - arrow - using the (T40058).
• The threaded holes - arrows - in the camshafts must face upward.
Left cylinder head:
- Remove the bolt - 1 -.
Right cylinder head:
- Remove the bolt - 2 -.
Continuation for both cylinder heads:
- Turn the crankshaft one full revolution (360°) in the direction of engine rotation - arrow - using the (T40058).
• The openings - arrows - on the exhaust camshafts must face toward the outer side of the engine.
Left cylinder head:
- Slide the unloaded camshaft sliders - B - and - C - as far as the stop in direction of - arrow -.
Right cylinder head:
- Slide the unloaded camshaft slider - F - as far as the stop in direction of - arrow -.
Continuation for both cylinder heads:
- Turn the crankshaft one full revolution (360°) in the direction of engine rotation - arrow - using the (T40058).
• The threaded holes - arrows - in the camshafts must face upward.
- Remove the camshaft timing chains from the camshafts. Refer to => [ Camshaft Timing Chains, Removing from Camshafts ] Camshaft Timing Chains, Removing from Camshafts.
CAUTION!
Risk of damaging valves and piston crowns.
• If the camshaft timing chain was also only removed on one cylinder head, the crankshaft must not be rotated any more.
Left cylinder head:
- Remove the bolts - 3 through 9 - while sliding the unloaded camshaft slider - A - accordingly.
- Remove the cylinder head.
Right cylinder head:
- Remove the bolts - 10 through 16 - while sliding the unloaded camshaft sliders - D - and - E - accordingly.
- Remove the cylinder head.
Installing
• Tightening specifications, refer to => [ Cylinder Head Assembly Overview ] Cylinder Head Assembly Overview.
CAUTION!
The sealing surfaces could be damaged.
• Carefully remove sealant residue from cylinder head and cylinder block.
• Make sure that no long scrapes or scratches result.
Risk of damaging cylinder block.
• There must be no oil or coolant in the blind holes for the cylinder head bolts in the cylinder block.
Risk of cylinder head seal leaking.
• Carefully remove all grinding and sanding residue.
• Only unpack new cylinder head gasket immediately prior to installation.
• To prevent cylinder head seal silicone layer and recessed area from being damaged, always handle seal extremely carefully.
Risk of damaging open valves.
• If a replacement cylinder is installed, only remove plastic base right before cylinder head is installed to protect open valves.
Risk of damaging valves and piston heads after working on valvetrain.
• To ensure valves do not strike pistons when starting, carefully rotate engine at least 2 full revolutions.
• Replace bolts which have been tightened to torque.
• Replace sealing rings, seals and self-locking nuts.
• Note different sealant for cylinder head sealing surfaces and bolts.
• If a replacement cylinder is installed, the contact surfaces between the hydraulic adjusting elements, roller rocker levers and cam running surfaces must be lubricated before installing the cylinder head cover.
• Secure all hose connections with hose clamps appropriate for the model.
• The engine oil and coolant must be changed if the cylinder head or cylinder head seal are replaced.
- Before installing the cylinder head, set the crankshaft and camshafts to "TDC" and install the (T40133) on both cylinder heads and tighten to 25 Nm - arrows -.
• The (T40133) is correctly positioned when the holes for the cylinder head bolts remain free.
• (T40069) must be screwed into the crankshaft.
- Set cylinder head gasket in place.
• Pay close attention to centering pins - arrows - in cylinder block.
• Cylinder head seal installation position: Identification "oben" (top) or the cylinder head part number.
- Position the cylinder head.
Left cylinder head:
- Insert the bolts - 1 through 7 - while sliding the unloaded camshaft slider - A - accordingly.
- Tighten the bolts in 3 steps following the sequence - 1 to 7 -. Refer to => [ Cylinder Head Assembly Overview ] Cylinder Head Assembly Overview.
Right cylinder head:
- Insert the bolts - 8 through 14 - while sliding the unloaded - D - and - E - accordingly.
Camshaft sliders
- Tighten the bolts in 3 steps following the sequence - 8 to 14 -. Refer to => [ Cylinder Head Assembly Overview ] Cylinder Head Assembly Overview.
Continuation for both cylinder heads:
- Position the camshaft timing chain on the camshafts => [ Installing ] Camshaft Timing Chains, Removing from Camshafts.
- Remove the (T40133) and the (T40069).
- Turn the crankshaft one full revolution (360°) in the direction of engine rotation - arrow - using the (T40058).
• The openings - arrows - on the exhaust camshafts must face toward the outer side of the engine.
Left cylinder head:
- Slide the unloaded camshaft sliders - B - and - C - as far as the stop in direction of - arrow -.
Right cylinder head:
- Slide the unloaded camshaft slider - F - as far as the stop in direction of - arrow -.
Continuation for both cylinder heads:
- Turn the crankshaft one full revolution (360°) in the direction of engine rotation - arrow - using the (T40058).
• The threaded holes - arrows - in the camshafts must face upward.
Left cylinder head:
- Insert the bolt - 15 - and tighten it in 3 steps. Refer to => [ Cylinder Head Assembly Overview ] Cylinder Head Assembly Overview.
Right cylinder head:
- Insert the bolt - 16 - and tighten it in 3 steps. Refer to => [ Cylinder Head Assembly Overview ] Cylinder Head Assembly Overview.
Continuation for both cylinder heads:
- Turn the crankshaft one full revolution (360°) in the direction of engine rotation - arrow - using the (T40058).
• The openings - arrows - on the exhaust camshafts must face toward the outer side of the engine.
Left cylinder head:
- Slide the unloaded camshaft slider - B - as far as the stop in direction of - arrow -.
Right cylinder head:
- Slide the unloaded camshaft slider - F - as far as the stop in direction of - arrow -.
Continuation for both cylinder heads:
- Tighten the bolts - arrows -.
• Left cylinder head: 3 bolts.
• Right cylinder head: 4 bolts.
• Bolts must not be tightened after repairs.
The rest of the installation is in reverse order of removal, note the following:
- Install the left and right timing chain covers => [ Installing ] Left and Right Timing Chain Covers.
- Install the cylinder head cover. Refer to => [ Left Cylinder Head Cover ] Left Cylinder Head Cover or => [ Right Cylinder Head Cover ] Right Cylinder Head Cover.
- Install the lower section of the intake manifold.
- Install the upper section of the intake manifold.
- Install front coolant pipe. Refer to => [ Front Coolant Pipe ] Front Coolant Pipe.
- Install ribbed belt. Refer to => [ Ribbed Belt ] Ribbed Belt.
- Install the front exhaust pipe and catalytic converter. Refer to => [ Left Front Exhaust Pipe with Catalytic Converter ] Left Front Exhaust Pipe with Catalytic Converter, and for the => [ Right Exhaust Pipe with Catalytic Converter ] Right Exhaust Pipe with Catalytic Converter.
- Change engine oil.
- Replace coolant. Refer to => [ Cooling System, Draining and Filling ] Procedures.