Audi Workshop Service and Repair Manuals > A3 Mk1 > Power unit | 4-cylinder 1.8 ltr. 5-valve turbocharged engine (110-132 kW), mechanics | Exhaust system | Secondary air system - not on engine code AGU, AJQ, AQA | Checking combination valve for secondary air system for proper operation and leakage

Checking combination valve for secondary air system for proper operation and leakage

Special tools and workshop equipment required

t	Hand-operated vacuum pump with accessories -V.A.G 1390-

Procedure

l	Vacuum hoses and hose connections do not leak.

l	Vacuum hoses are not clogged.

–	Take off engine cover panel -arrows-.

–	Remove cover in front of intake manifold -arrows-.

–	Detach air hose -1- leading to secondary air pump at air cleaner housing.

–	Release hose clip -2- and detach air duct from air mass meter -G70-.

–	Unplug electrical connector at air mass meter -G70- -item 3-.

–	Unscrew bolts -4- and -5- and remove air cleaner housing.

–	Detach vacuum hose -2- from combination valve for secondary air system.

–	Connect the hand-operated vacuum pump -V.A.G 1390- to vacuum connection of combination valve for secondary air.

–	Disconnect air hose -arrow- at secondary air pump.

–	Connect suitable test hose to air hose connection on secondary air pump.

–	Blow gently into hose (do not use compressed air).

l	The combination valve for secondary air should be closed; it should not be possible to blow through the hose.

–	Use hand-operated vacuum pump to generate vacuum.

l	The combination valve for secondary air should open; it should now be possible to blow through the hose.

If combination valve for secondary air does not react as described:

–	Renew secondary air combination valve → Chapter.

Installation is carried out in the reverse order; note the following:

Note

Secure all hose connections with the correct type of hose clips (same as original equipment) → Parts catalogue.

Audi Workshop Service and Repair Manuals