Removal and installation of the exhaust system (BMW 3 Series E30)

Removal

Raise the car.

Cover all bolted connections with rust solvent and wait until it takes effect.

Unscrew the front pipe from the exhaust manifold from below.

Support the exhaust system with a wooden support.

Vehicles with a catalytic converter: disconnect the lambda probe connector at the front of the front pipe. Unscrew the protective shield of the catalytic converter. Unscrew the lambda probe from the front muffler pipe. To avoid damaging the wire, turn it together with the probe.





Unscrew the side support of the muffler pipe.

Unscrew the end muffler holder.

With an assistant, lower the exhaust system.

Installation

Before installing the exhaust system, check that the flange connecting to the exhaust manifold is not bent and straighten it if necessary.

Coat the exhaust manifold studs with copper paste.

Place the front part of the exhaust system onto the manifold and tighten evenly with the new self-locking nuts.



Assemble the front pipe with the pre-silencer and tighten the clamp slightly. If necessary, clean the conical part of the front fur coat connection with sandpaper from carbon residue before assembly. When assembling, ensure that the sealing rings are installed correctly. Be sure to install new self-locking nuts.

Note: It is recommended to coat all bolts and nuts with a high temperature paste, such as Liqui Moly LM-508-ASC, to make them easier to remove later.

Cars with a catalytic converter: spray the lambda probe thread with "Antiseize" aerosol. On the 325e model, to avoid contact failure, seal the detachable connection with paste "3-Bond-Silicon". Screw the lambda probe into the front pipe and tighten to 55 Nm. Connect the connector. Screw on the protective shield.

Before tightening, align the exhaust system.





The flat part of the pipe must pass through the channel area.



The distance from the pipes to the body should be 25 mm. Otherwise, adjust the distance with the end muffler holder.



Secure the clamps of the final muffler so that they are under the tension of the rubber suspensions by approximately 6 mm. To do this, with the clamp released, move the final muffler slightly forward. This is necessary because during operation the exhaust system expands from heating and takes the correct position.



Tightening torques for threaded connections of the exhaust system:

• front pipe to exhaust manifold - 45 Nm;
• triangular flange threaded connections - 22 Nm;
• bracket on the gearbox and on the muffler - 22 Nm;
• holder on bracket, on rubber support - 10 nm;
• end silencer bracket, M20 bolts - max 14 Nm;
• tubular bracket of the catalyst, bolts M20 - 20 Nm, bolts M10/M30 - 22 Nm;
• heat shield of the catalyst - 7 nm.

Start the engine and check the exhaust system for leaks by covering the exhaust pipe with a rag.

Lower the car.