Checking the exhaust system for leaks (BMW 3 Series E46)

In vehicles with a regulated catalytic converter, a leak in the exhaust system can cause the following problems:

• Difficulties starting the engine.
• Engine vibrations at idle and engine stalls.
• Jerks when increasing engine speed.

Checking for leaks

1. Start the engine and cover the muffler with a rag.

2. Listen to the exhaust system. If necessary, spray the cylinder head/exhaust manifold and exhaust manifold/head pipe connections with leak detection solution and inspect for bubbles.

3. Eliminate leaks.