New Generation N62 Engine
Chapter 3 P.17
Course Contents/Background Material
© BMW AG,
Service Training
- Secondary air system
General information
Fig. 15: N62 air routing
Blowing additional air (secondary air) into the cylinder head
exhaust duct during the warm-up phase results in a thermal
secondary combustion which in turns results in a reduction of
the non-combusted hydrocarbons (HC) and carbon monoxide
(CO) contained in the exhaust vapours.
The energy generated during this process heats up the catalytic
converter faster during the warm-up phase, and increases its
conversion rate.
Index
Description
1
Air intake duct
2
Air cleaner housing with intake air silencer
3
Intake pipe with HFM (hot-film air-mass flow sensor)
4
Secondary air valves
5
Secondary air pump
KT-7888