Air Injection Control Valve: Service and Repair
Replacing Anti-Run-On Valve For Secondary Air
If the anti-run-on valve or the check valve are defective, the secondary air system must be converted to the system used as of model year 2000, see Carrera Technical Information 1/02 2669.
Diagram of secondary air injection as of model year 2000
Diagram Of Secondary Air Injection As Of Model Year 2000 (part 1):
Diagram Of Secondary Air Injection As Of Model Year 2000 (part 2):
Removing anti-run-on valve and check valve
CAUTION:
- Pentosin is hazardous to the health.
- Wear protective gloves and goggles. If the eyes or skin come into contact with the fluid, wash immediately with water.
- Collect emerging Pentosin.
- Protect the leads against soiling and damage with caps.
- Clean hoses thoroughly which come into contact with Pentosin.
CAUTION: Danger of scalding when the engine is hot; coolant is under pressure. Do not begin working until the engine has cooled down.
- Carefully open the cap on the expansion tank.
- Coolant is hazardous to the health and irritates the skin.
- When handling coolant, wear protective gloves and goggles.
- In case of contact with the skin or eyes, wash immediately with plenty of water.
1. Attach protective covers to the rear of the vehicle to avoid damaging the paint.
NOTE: Note the work instructions for disconnecting and reconnecting the battery.
2. Disconnect battery.
3. Remove air cleaner housing.
4. Remove throttle body. To do so, pull off the cable plug from the throttle body, undo the four M6 x 25 hexagon-head bolts and remove the throttle body.
Steps 5 - 6 refer to the adjacent Figure
5. Press together the plug connection on top and bottom of the central intake distributor -3- and pull out the pipe.
6. Disengage switch-over valve of the tank ventilation -4- from the plastic clip and pull off cable plug.
7. Remove coolant bleeder hose -arrow- by undoing the spring-band clamp and then pulling off the hose. Collect any draining water.
8. Remove central intake distributor by undoing all four screw-type hose clamps -2- and then pressing the rubber sleeves on the left and right off the central intake distributor with a suitable tool. Remove central intake distributor.
9. Remove the vacuum lines from both rubber sleeves and remove the rubber sleeves with the screw-type hose clamps.
10. In vehicles with air conditioning, the following work operations must be performed.
- a. Remove the drive belt from the belt pulley of the air-conditioning compressor. Mark the running direction of the belt with a colored pen. Slacken belt by turning the tensioning pulley (a/f 24) clockwise, hold still and simultaneously take the drive belt off the belt pulley of the air-conditioning compressor. Carefully allow the tensioning roller to turn back into tensioning position.
- b. Disconnect battery positive lead -1- at B+ disconnection point. Unscrew the hexagon nut M8 and remove the positive lead. Then unscrew the hexagon-head bolt M6 x 12 -2- at the holder and lay the holder and box to one side.
- c. Extract Pentosin fluid from the servo-tank with a pump. Dispose of extracted Pentosin according to the relevant regulations. Lay a cloth under the tank to collect any emerging Pentosin. Open the bayonet lock anti-clockwise and remove the tank. Immediately seal the lower tank opening with a plug ( approx. 30mm).
NOTE: After removal, place the air-conditioning compressor on a suitable protective support (e.g. foam, neoprene).
- d. Remove the air-conditioning compressor. Tool recommendation: 1/4 inch -Figure d3-. 3 hexagon-head bolts M8: Unscrew 2 bolts at rear -1-, 1 at front -2-. For better access to the front threaded part -2-, remove the engine compartment temperature sensor with the rubber sleeve at the right intake distributor.
Front threaded part, air-conditioning compressor
Figure d3: recommended 1/4 inch tool for the front compressor screw
- e. Lift out air-conditioning compressor with connected leads. To do so, pull up the front fastening screw in the aluminium spacer sleeve and hold it tight. Disconnect the ground cable from the plug connection and lay it to one side on a protective support. Also secure against falling down (tie wraps).
11. Remove hose from the secondary pump -4-.
12. Remove generator.
13. Remove the cable plug of the knock sensor (cylinder bank 1 - 3) -1- and unscrew the M8 hexagon-head bolt of the knock sensor -2- ; then remove the knock sensor. Unscrew the air line union nut (hexagon a/f 22) -3- on the distributor housing.
14. Remove cable plug of the oil level sender and remove the aluminium spacer sleeve -2-. Unscrew 2 M6 x 16 hexagon-head bolts -1- for the air line on cylinder head 4 - 6, remove air line and metal seal.
15. On cylinder bank 1 - 3, remove the wire retainer from the intake pipe -3- by unclipping the wiring harness and unscrewing the M6 hexagon-head bolt. Disconnect vacuum line from the anti-run-on valve -1-. Using spring-band pliers, remove the clamp from the hose to the secondary air pump -2- and pull off the hose.
16. Undo the screw on the vacuum reservoir with a crosshead screwdriver -arrow- and press the vacuum reservoir to the rear.
17. Unscrew the 2 M6 x 20 hexagon-head bolts for the distributor housing on the cylinder head 1 - 3. Unclip switch-over valve on distributor housing. Remove distributor housing with check valve from the engine.
Installing anti-run-on valve and check valve
1. Clean the sealing surfaces on both cylinder heads with a clean cloth soaked in cleaning fluid (e.g. solvent naphtha, acetone).
2. Prepare new parts for installation. Mount anti-run-on valve (combination valve) with seal and 2 M6 x 16 hexagon-head bolts on the distributor housing.
Tightening torque 10 Nm (7.5 ft.lb.)
The illustration shows the new distributor housing with anti-run-on valve (combination valve), seals and screws
3. Position distributor housing on cylinder bank 1 - 3 with fitted combination valve and new seal but without air line. To do so, screw in two M6 x 20 hexagon-head bolts by hand. Position air line with new seal on the flange of cylinder bank 4 - 6, and place union nut a/f 22 in position on the distributor housing. Fasten the air line into position by hand with two M6 x 16 hexagon-head bolts (cylinder bank 4 - 6), and tighten the union nut a/f 22 with a torque wrench. Screw all four M6 hexagon-head bolts tight.
Tightening torque for M6 hexagon-head bolts 10 Nm (7.5 ft.lb.)
Tightening torque for union nut a/f 22 25 Nm (19 ft.lb.)
4. Press vacuum reservoir into the distributor housing from the rear and tighten fastening screw -arrow-.
5. Clip switch-over valve into distributor housing.
6. On cylinder bank 1 - 3, fit wire retainer on the intake pipe with an M6 hexagon-head bolt, then clip wiring harness into place.
Tightening torque 10 Nm (7.5 ft.lb.)
NOTE: When installing the knock sensor, make sure that all surfaces are clean and that the correct tightening torque is observed precisely.
7. Install knock sensor by tightening the M8 hexagon-head bolt of the knock sensor (cylinder bank 1 - 3) and connecting the cable plug of the knock sensor.
Tightening torque: 23 Nm (17 ft.lb.)
8. Fit new hose to the secondary air pump using a spring-band clamp at the combination valve -2- and connect the vacuum hose -1- to the combination valve.
9. Install generator.
10. Fit air hose to the secondary air pump -4-.
11. On cylinder bank 4 - 6, connect cable plug of the oil level sender and the aluminium spacer sleeve -2-.
12. In vehicles with air conditioning, install air-conditioning compressor.
13. Position rubber sleeves with loose screw-type hose clamps on the left and right of the intake distributor and push as far as possible in the direction of the intake plenum. Insert vacuum lines into rubber sleeves.
14. Install central intake distributor by spraying the left and right rubber sleeves with silicone spray and pushing the central intake distributor into place. Align the rubber sleeves and tighten all four screw-type hose clamps -2-.
15. Install coolant bleeder hose -arrow- by pushing on the spring-band clamp and fastening the hose to the plastic flange.
Steps 6 - 17 refer to the adjacent Figure
16. Connect plug connection to central intake distributor -3-.
17. Clip switch-over valve of the tank ventilation -4- into the plastic clip and connect cable plug.
18. Install throttle body. To do so, position the throttle body with new sealing ring and tighten the four M6 x 25 hexagon-head bolts. Fit cable plug to the throttle body.
19. Install air cleaner housing.
NOTE: Note the work instructions for disconnecting and reconnecting the battery.
20. Connect the battery.
21. Check fluid levels (coolant and Pentosin) and fill in, if necessary.
22. Remove protective covers from rear of vehicle.
