Exhaust Manifold: Service and Repair

Exhaust manifold / gasket, replacing

Special tools:
999 5543 SOCKET NV-22 HO2S 999 5543 Socket NV-22 HO2S

Note! As the illustrations in this service information are used for different model years and / or models, some variation may occur. However, the essential information is always correct.

Preparation

Remove
- the right front wheel
- the splash guard under the engine
- the right drive shaft. See Half shaft, right, replacing, B5254T2, M58, B5254T2, M56 Half Shaft, Right, Replacing.





Remove
- the heat deflector plate above the coolant pipes and hoses for the oil cooler
- the support bracket between the cylinder block and the manifold and three-way catalytic converter (TWC)
- the nuts where the front exhaust pipe and three-way catalytic converter (TWC) join.

Remove the brake pipe from the holders at the front SIPS member.
Remove the screws holding the SIPS member to the bodywork.
Unhook the rubber mountings for the rear exhaust system from the holders.
Pull the exhaust system back so that it releases from the flange at the manifold and three-way catalytic converter (TWC). Put it to one side.





Remove
- the engine stabilizer brace between the suspension turrets
- the air preheating hose between the air cleaner (ACL) and the heat deflector plate.

Disconnect the connector for the front heated oxygen sensor (HO2S).
Remove the heated oxygen sensor (HO2S) wiring from the rear engine mounting.
Remove the front heated oxygen sensor (HO2S).
Seal the opening for the heated oxygen sensor (HO2S).
Remove the upper heat deflector plate over the manifold.

Right-hand drive only
Remove the lower heat deflector plate over the three-way catalytic converter (TWC).

Removing the exhaust manifold and three-way catalytic converter (TWC)





Remove (left-hand drive cars)
- the nuts securing the manifold and the three-way catalytic converter (TWC) to the cylinder head
- lift the manifold and three-way catalytic converter (TWC) off the studs at the cylinder head
- the gaskets.

Remove (right-hand drive cars)
- the nuts securing the manifold and the three-way catalytic converter (TWC) to the cylinder head
- lift the manifold and three-way catalytic converter (TWC) off the studs at the cylinder head. Place to one side
- the heat deflector plate over the steering gear
- the upper collision guard at the steering gear.
Lift the manifold and three-way catalytic converter (TWC) out.
Remove the gaskets.

Note! Note the process for removal. This will make installation easier.

Installing the exhaust manifold and three-way catalytic converter (TWC)

Note! For tightening torques, see: Tightening torque Tightening Torque.

Note! To ensure that there is no exhaust leakage, see: Flanged joint, assembling Flanged Joint, Assembling.





Clean the gasket faces. Check that the studs are tightened.
Install new gaskets.
Lubricate the studs. Use paste 116 1408.

Warning! Avoid skin contact with the paste.

Seal the thread for the upper heated oxygen sensor (HO2S).

Right-hand drive only
Lift the manifold and three-way catalytic converter (TWC). Put it to one side.

Install (right-hand drive cars)
- the heat deflector plate over the steering gear. Tighten the screws
- the manifold and the three-way catalytic converter (TWC). Check that the gaskets are correctly positioned
- the upper collision guard at the steering gear. Tighten the screws. Tighten to 80 Nm.

Left-hand drive cars only
Lift and install the manifold and three-way catalytic converter (TWC). Check that the gaskets are correctly positioned.





Install (right-hand drive cars)
- the nuts securing the manifold to the cylinder head. Use new nuts. Do not tighten
- the lower heat deflector plate over the three-way catalytic converter (TWC). Do not tighten.

Tighten all the nuts securing the manifold to the cylinder head. Tighten to 25 Nm.

Install (right-hand drive cars)
- the upper heat deflector plate above the manifold
- the screws. Tighten all the screws holding the heat deflector plates.

Install (left-hand drive cars)
- the nuts securing the manifold to the cylinder head. Use new nuts. Tighten to 25Nm
- the heat deflector plate above the manifold.

Install the upper heated oxygen sensor (HO2S). Lubricate the threads. Use paste 116 1408.

Warning! Avoid skin contact with the paste.

Tighten the heated oxygen sensor (HO2S). Tighten to 45 Nm. Use tool 999 5543 SOCKET NV-22 HO2S 999 5543 Socket NV-22 HO2S.
Connect the connectors for the heated oxygen sensor (HO2S) to the wiring at the rear edge of the transmission.
Secure the heated oxygen sensor (HO2S) wiring at the rear engine mounting (2 mounting points).

Finishing





Install
- the air preheating hose between the heat deflector plate and the air cleaner (ACL)
- the engine stabilizer brace between the suspension turrets.





Install
- the front exhaust pipe on the manifold and three-way catalytic converter (TWC). Use a new gasket and new nuts. Lubricate the threads with paste 116 1408. Tighten the nuts. Tighten to 25 Nm.

Warning! Avoid skin contact with the paste.

- the rubber mounting for the rear exhaust system
- the front SIPS member. Tighten to 25 Nm
- the brake pipe on the plastic holders at the front SIPS member
- the support bracket between the cylinder block and the manifold and three-way catalytic converter (TWC). Tighten the screws
- the heat deflector plate above the coolant pipes and hoses
- the right drive shaft. See Half shaft, right, replacing, B5254T2, M58, B5254T2, M56 Half Shaft, Right, Replacing
- the splash guard under the engine
- the right front wheel. See Installing wheels Service and Repair.

Check
Test run the engine. Check for any leakage from the exhaust system and manifold.