BMW 1 Quiz
Fuel and Exhaust Systems

Exhaust System Leak Check

In this manual: Fuel and Exhaust Systems
Introduction — 10Owner's Manual — 29Routine Care and Maintenance — 30Engine — 18Cooling and Heating Systems — 13Fuel and Exhaust Systems — 29Engine Electrical Equipment — 20Manual Transmission — 4Automatic Transmission — 4Clutch and Drive Shafts — 12Brake System — 19Suspension and Steering — 22Body — 36Body Electrical Equipment — 34Electrical Circuit Diagrams — 30On-board diagnostic system — 5
~1min read

An exhaust leak upstream of the oxygen sensor on the system with the catalytic converter can cause faults such as difficult engine starting. The engine may stall, vibrate at idle, or increase speed in jerks.

* Test condition: Engine must be cold or slightly warm.

CHECK
1. Start the engine and check the exhaust system for leaks. Block the tailpipe with rags. Check for exhaust gas leaks at the flange connections (by sound, hissing, or by hand).
2. Spray the joints between the cylinder head and exhaust manifold, and between the manifold and front pipe, with soapy solution and check for bubbles.

Test yourself

A quick BMW 1 quiz: every answer comes with an explanation and a link to the manual page.