Change Car Rear Silencer
The rear silencer is the last part of the exhaust system. Its job is to reduce the noise of the exhaust gases before they are released into the atmosphere. A perforated or noisy silencer is penalised at the MOT and can earn you a fine if you are stopped on the road.
Worth knowing
The rear silencer is only one part of the exhaust system. The whole system also includes the manifold, the catalytic converter, the centre silencer and the connecting pipes. Only the rear silencer is covered here: it is the part most often replaced because it is exposed to water spray and corrosion.
When does the rear silencer need replacing?
No replacement interval is set in the service schedule. In general, the rear silencer is changed between 60,000 and 130,000 km. Replace it if it shows advanced corrosion, perforation, or if abnormal noises appear.
Key points for the replacement
Difficulty 2/5
Technically accessible, but needs a jack, axle stands, and sometimes an exhaust chain cutter if the clamp is seized by corrosion. Apply releasing fluid beforehand.
Connecting sleeve
If you have to cut the exhaust pipe, a connecting sleeve joins it to the new silencer (around £12). For any residual leak, exhaust paste solves the problem.
Rubber mounts
Check the condition of the exhaust rubber mounts and replace them if needed (around £5 to £15 each). Worn mounts cause knocking noises under the car.
Price
A rear silencer costs between £60 and £300 depending on the model. Average garage price: around £300, excluding labour.
When to replace?
Excessive noise
A holed or cracked silencer produces a booming or droning noise, especially under acceleration. The MOT penalises an excessive noise level.
Visible corrosion
Advanced rust, holes or condensation marks on the silencer body. Corrosion is the main cause of failure, accelerated by short trips that prevent the internal condensation from evaporating.
Vibration or knocking
A broken mounting rubber or a loose clamp causes vibration transmitted to the body. Check the mountings before replacing the silencer.
