Exhaust System: Service and Repair

Exhaust System, Inspection/Overhaul





Sealing
The system must not only be well sealed, but must also be assembled from components made to manufacturer's specifications, to ensure optimum engine performance and guarantee the cleaning efficiency of the catalytic converter.

New gaskets must be used when fitting components.


Exhaust manifold, replacement





Release front exhaust pipe
Remove nuts in joint with manifold.

Undo joint between catalytic converter and front silencer.





Remove heat shields
Disconnect air preheating hose.

Remove top and bottom heat shields.

Disconnect front exhaust pipe from bracket on flywheel housing.





Remove exhaust manifold and gasket
Inspect faces of joints with cylinder head and front exhaust pipe.





Install exhaust manifold
Use new gasket.

Tighten manifold on cylinder head.

Attach lifting lug to upper row of bolts between No.2 and No.3 exhaust branches.





Install front exhaust pipe
Use new gasket.

Tighten joint with manifold.

Tighten joint at front of catalytic converter/silencer.





Install heat shields
Tighten exhaust pipe to bracket on flywheel housing.

Reconnect air preheating hose.

Check operation
Start engine.

Check system for leaks.


Exhaust pipe, replacement





General
Use new gaskets.

Replace conical steel ring in clamped joint on front exhaust pipe only if damaged.

Inspect rubber mountings and replace if necessary.

Pipe sections should overlap by approx. 40 mm (1112 in).

Clearance between exhaust system and body should not be less than 20 mm (3/4 in).

NOTE: Ensure that oxygen sensor wiring is protected against strain when replacing exhaust systems on cars with catalytic converters.





Installation of complete system
Follow procedure below to avoid stresses in system:

Install front pipe and tighten bolted joint with manifold.

Insert and tighten mounting bolts in front pipe bracket.

Offer up and align other components.

Tighten pipe/silencer clamps.

Tighten nuts at front pipe pivot point.

Check clearance between system and body. Adjust as required.





Check operation
Start engine.

Check system for leaks.


Catalytic converter





General
Different catalytic converters are used depending on engine type, model year and market.

Each converter provided with a plate stating the part number and other details.

The unit is also marked with an arrow to indicate the direction of flow.





Connection to front exhaust pipe
Catalytic converter flange is fitted with fixed bolts.

Bolts may be replaced with separate bolts in the event of damage.





Check catalytic converter
Converter efficiency may be checked by measuring and comparing CO content before and after unit.

Converter reduces CO content on reaching ignition temperature (450°C/840°F).