Cylinder Heads
Cylinder Heads
Special tools, testers and auxiliary items required
• Locking Pin (T40071)
• Camshaft Clamp (T40133)
• Locking Pin (T40069)
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.
• During installation, all cable ties must be installed at the same location.
There is a risk of injury because the fuel is under very high pressure.
• Reduce the fuel pressure down to residual pressure before opening high pressure area of the fuel injection system.
- Reduce fuel pressure in high pressure area.
- Remove the upper coolant pipe. Refer to => [ Upper Coolant Pipe ] Upper Coolant Pipe.
- Remove the oil filter housing. Refer to => [ Oil Filter Housing ] Oil Filter Housing.
- Disconnect the connector - 1 -.
- Remove the bolt - 2 -.
- Open the clamps - arrows - and remove the coolant hoses from the coolant reservoir.
- Remove the lower section of the intake manifold.
- Disconnect the electrical connectors on the fuel injectors.
- Remove the affected camshaft timing chain from camshafts. Refer to => [ Camshaft Timing Chains, Removing from Camshafts ] Camshaft Timing Chains, Removing From Camshafts.
- Remove the (T40071) from the left cylinder head.
- Remove the bolts - 1 and 2 - and then remove the chain tensioner on the right cylinder head.
• The (T40071) remains inserted.
- Disconnect the connectors from the left cylinder head
1 For Camshaft Position (CMP) sensor 2 (G163)
3 For camshaft adjustment valve 2 (N208)
- Move the electrical wiring harness to the side.
• Ignore items - 2 - and - arrows -.
- Disconnect electrical connector - 1 - for Engine Coolant Temperature (ECT) sensor (G62).
- Remove the front coolant pipe bolts - arrows -.
- Remove the threaded connection - 1 - and move the fuel supply line to the side.
- Disconnect electrical connectors - 2 - and - 3 -.
- Remove the Ground (GND) wire bolt - 1 -.
• Ignore - 2 -.
- Disconnect the connectors from the right cylinder head.
1. Camshaft adjustment valve 1 (N205)
2. Camshaft position sensor (G40)
- Move the electrical wiring harness to the side.
• Ignore - arrows -.
- Remove the bolt - arrow - and remove the oil dipstick and guide tube.
- Open the clamp - 1 - and remove the vacuum hose from the vacuum pump.
• Ignore - arrows -.
- Remove the bolts - arrows - on the rear of the cylinder head.
• Left cylinder head: 3 bolts.
• Right cylinder head: 4 bolts
- Loosen the cylinder head bolts in the following sequence - 1 through 8 -.
- Remove the bolts, remove the cylinder head and place it on a soft surface (foam).
Installing
Tightening specifications:
• => [ Cylinder Head Overview ] Cylinder Head Overview
• => [ Cylinder Head, Tightening Specifications and Sequence ] Cylinder Head Overview
• => [ Lower Timing Chain Cover, Tightening Specifications and Sequence ] Timing Chain Covers Overview
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 an additional torque.
• Replace self-locking nuts, sealing rings, seals and O-rings.
• 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, refer to the Parts Catalog.
• The coolant and engine oil must be changed whenever replacing the cylinder head or cylinder head seal.
• Secure the camshafts in the Top Dead Center (TDC) position on both cylinder heads using the (T40133) - arrows - (25 Nm).
• The (T40133) is correctly positioned when the holes for the cylinder head bolts remain free.
• Secure crankshaft - 1 - in TDC position using the (T40069).
- Install new seals and O-rings for the front coolant pipe.
- Set cylinder head gasket in place.
• Installation position: The marking "top" or the part number must be legible.
• Pay close attention to alignment bushings in cylinder block - arrows -.
- Set cylinder head in place.
- Tighten the cylinder head bolts. Refer to => [ Cylinder Head, Tightening Specifications and Sequence ] Cylinder Head Overview.
- Tighten the bolts - arrows - for the lower timing chain cover. Refer to => [ Lower Timing Chain Cover, Tightening Specifications and Sequence ] Timing Chain Covers Overview.
• Left cylinder head: 3 bolts.
• Right cylinder head: 4 bolts.
• There is no requirement to tighten the cylinder head bolts after repairs.
The rest of the installation is performed in reverse order of removal, noting the following:
- Install oil dipstick guide tube. Refer to => [ Oil Dipstick Guide Tube - Tightening Specifications ] Cylinder Head Overview.
- Install front coolant pipe. Refer to => [ Front Coolant Pipe ] Front Coolant Pipe.
- Install the camshaft timing chains. Refer to => [ Camshaft Timing Chains ] Camshaft Timing Chains.
- Electrical connections and routing.
- Install the lower section of the intake manifold.
- Connect the coolant hose to the coupling. Refer to => [ Connect the Coolant Hose to the Coupling ] Radiator Overview.
- Install the oil filter housing. Refer to => [ Oil Filter Housing ] Oil Filter Housing.
- Install the upper coolant pipe. Refer to => [ Upper Coolant Pipe ] Upper Coolant Pipe.
- Change engine oil.
- Replace coolant. Refer to => [ Cooling System, Draining and Filling ] Service and Repair.