Exhaust system components — removal and installation (BMW 7 Series E32)

All parts of the exhaust system can be replaced separately.

Caution: When installing the exhaust system parts, make sure that the parts fit tightly together. Otherwise, incorrect data on the concentration of toxic substances will be obtained.

After removing the self-locking nut, the gaskets must be replaced. The mounting rings and rubber hangers must be checked for integrity and damage, and replaced if necessary.

When installing a new exhaust system, it is recommended to also replace all mounting parts.

Removal

Raise and support the vehicle and remove the lower engine cover.

Apply a penetrating rust dissolving compound to all threaded connections and wait for the compound to take effect. Unscrew the nuts from the end muffler holder.



Support the exhaust system with a floor jack and a suitable support, such as a wooden one. The system weighs between 35 and 45 kg.



Remove the bolts and disconnect the front exhaust pipe from the exhaust manifold (gasoline engines) or from a turbocharger.





Remove the bolts and disconnect the exhaust system from the support on the gearbox.



Unhook the exhaust system from the rubber mounts (hangers) and remove it.

Caution: The catalytic converter is sensitive to impacts and should not be knocked or dropped.

Installation

Before installing the exhaust system, check that the flange mating with the exhaust manifold is not deformed and, if necessary, align the flange.

Note: To make it easier to loosen the exhaust system nuts and bolts later, it is recommended to lubricate them with a high-temperature lubricant based on meoi.

Install the exhaust system and secure it with the holders. Do not tighten the bolts and nuts yet.

Align the exhaust system so that there is a minimum distance of 25 mm from all its parts to the body. In addition, the end exhaust pipe should be positioned evenly in the recess of the body at the rear.



Diesel engine: Install the front exhaust pipe to the turbocharger and secure it with bolts/nuts. Pre-check the sealing ring, replace it if necessary. Lubricate the sealing ring with high-temperature copper-based grease.

Petrol engines: Install the front exhaust pipe to the inlet manifold with a new gasket and tighten the new self-locking nuts evenly. Tighten the bolts to 30 Nm. Then tighten the bolts to 50 Nm on a second pass.

Tighten all bolts and nuts. Tighten the exhaust system fastenings to the gearbox last so that they sit without tension.

Tightening torques

• Exhaust pipe fastenings to the exhaust manifold - 50 Nm.
• Threaded connections on a triangular flange - 20 Nm.

Mounting the exhaust system to the gearbox:

• parts with M6 thread - 10 Nm;
• parts with M8 thread - 20 Nm;
• fastening earrings - 20 Nm;
• clamps of the final muffler - no more than 15 Nm.

Install the crossbar, tighten the bolts to 20 Nm.

Start the engine and check the exhaust system for leaks by plugging the exhaust pipe with a rag. At the same time, an assistant should check all connection points for exhaust leaks (a hissing sound or emissions felt by the hand).

Install the lower engine splash guard (cover).