Cowl: Service and Repair
WM 508119 Removing and installing cross panel (disassembling plenum panel)
Technical values
Preliminary work
Information
Disassembling the plenum panel (removing the cross panel) is a preliminary step for ensuring access to the following components:
- High-pressure pump, vacuum pump
- Secondary air valves, secondary-air hoses
- Solenoid valve for valve lift switchover
- Cables, hoses at rear of cylinder heads
- Brake booster, brake master cylinder
- and so on.
1. Remove plenum panel cover. -> 852219 Removing and installing plenum panel cover 852219 Removing and installing plenum panel cover
2. Remove cowl panel cover. -> 508719 Removing and installing cowl panel cover - section on "Removing" Service and Repair
3. Remove wiper linkage for front wiper. -> 921919 Removing and installing wiper linkage
Information
Component overview
Assembly overview for plenum panel (cross panel)
Centre plenum panel at the top
Centre plenum panel at the bottom
Strut and plenum panel mounting
Removing cross panel
1. Remove the two foam pads at the sides of the wing. => Two foam pads at the sides
Two foam pads at the sides
2. Remove right plenum panel wall.
2.1. Disconnect cable plugs on the two sensors (prevents damage to the plugs during subsequent work). -1 and 2- Ensure that you detach the cable plug -1 - from the spring strut vertically (risk of breakage).
Right-hand side plenum panel wall at the periphery
2.2. Detach and expose wiring harness at the plenum panel wall. -3-
2.3. Remove fastening screws on the right plenum panel wall. => Mounting for right-hand side plenum panel wall
Mounting for right-hand side plenum panel wall
2.4. Remove plenum panel wall.
3. Remove left plenum panel wall.
3.1. Disconnect cable plugs on the two sensors -1 and 2- (prevents damage to the plugs during subsequent work). Ensure that you detach the cable plug from the spring strut -1 - vertically (risk of breakage).
Left-hand side plenum panel wall at the periphery
3.2. Detach and expose wiring harness at the plenum panel wall. -3-
3.3. Remove fastening screws on the left plenum panel wall. => Mounting for left-hand side plenum panel wall
Mounting for left-hand side plenum panel wall
3.4. Remove plenum panel wall.
4. Detach relay box from the strut. To do this, press the plastic hook -1- and set the relay box aside.
Relay box on strut
5. Clamp heater and coolant hoses on both sides of the centre plenum panel wall at the top using suitable hose clamps. => Clamped hoses (examples of hose clamps that can be used)
Clamped hoses (examples of hose clamps that can be used)
5.1. Disconnect hoses by releasing the locking clips and pull them off -1-. Soak up residual coolant with a cloth.
Disconnected hoses
5.2. Move locking clips back into installation position again immediately after removing the hoses.
6. Pull engine wiring harness out of the centre plenum panel wall. -2-
Engine wiring harness and vacuum line
7. Pull vacuum line off the vacuum pump. -3-
8. Remove centre plenum panel wall at the top.
8.1. Remove fastening screws. => Centre plenum panel at the top
Centre plenum panel at the top
8.2. Lift the centre plenum panel wall at the top and pull the vacuum line through the bore in the grommet. => Guiding vacuum line through the plenum panel wall
Guiding vacuum line through the plenum panel wall
9. Remove strut (A-strut).
9.1. Detach lines (vacuum, tank vent, fuel) and remove plastic clip. -4 and 5- Release the plastic clip by inserting a screwdriver through the side hole in the strut and pull it off.
Cable holder and lines
9.2. Remove fastening screws and nuts on the strut (A-strut). => Strut and plenum panel mounting -1 and 2-
Strut and plenum panel mounting
Strut mounting
9.3. Detach wiring harness under the strut and press holder out carefully.
Wiring harness for strut
9.4. Release two large cable plugs on the strut. To do this, press the two plugs out of the strut from behind.
9.5. Get another mechanic to help you guide the strut out sideways under the brake fluid reservoir. => Removing strut
Removing strut
10. Fold up foam pads on both sides. => Foam pads
Foam pads
11. Remove side cover (seal) at the right. => Side seal at the right
Side seal at the right
12. Remove centre cover (centre plenum panel wall) at the bottom. => Centre plenum panel at the bottom
Centre plenum panel at the bottom
12.1. Get another mechanic to help you lift the centre plenum panel at the bottom to the right and remove it.
12.2. Remove seal on centre plenum panel at the bottom on the removed plenum panel. => Seal on centre cover at the bottom
Seal on centre cover at the bottom
Installing cross panel
Information
Always replace seals and foam pads that are damaged or hard.
1. Before re-installing the centre plenum panel at the bottom, first fit the seal on the edge of the plate and spray with commercially available silicone spray (this makes it easier to push on the plenum panel wall). => Seal on centre plenum panel at the bottom
Seal on centre plenum panel at the bottom
2. Fit centre cover (centre plenum panel wall) at the bottom. => Centre plenum panel at the bottom
Centre plenum panel at the bottom
2.1. Get another mechanic to help you move the centre plenum panel wall at the bottom into installation position and press on the seal. Align the plenum panel wall.
3. Fit side cover (seal) at the right. => Side seal at the right
Side seal at the right
4. Fit foam pads on both sides. => Foam pads
Foam pads
5. Fit strut (A-strut).
5.1. Get another mechanic to help you guide the strut sideways under the brake fluid reservoir and over the centre plenum panel wall into installation position. The screw positions must be aligned. Place strut on the stud under the windscreen. => Fitting strut
Fitting strut
5.2. Fit two large cable plugs on the strut. To do this, press the two plugs sideways into the strut.
5.3. Press in wiring harness under the strut. => Wiring harness for strut
Wiring harness for strut
5.4. Fit fastening screws and nuts on the strut (A-strut). => Strut and plenum panel mounting -1 and 2-
Strut and plenum panel mounting
Strut mounting
5.5. Fit lines (vacuum, tank vent, fuel) and plastic clip. -4 and 5- Fit (clip in) the plastic clip on the strut.
Cable holder and lines
6. Fit centre plenum panel wall at the top.
6.1. Guide the centre plenum panel wall at the top in sideways under the wiring harness and pull the vacuum line through the bore in the grommet. Fit the grommet. => Guiding vacuum line through the plenum panel wall
Guiding vacuum line through the plenum panel wall
6.2. Align the centre plenum panel wall at the top and move it into installation position. Fit the fastening screws. => Centre plenum panel at the top
Centre plenum panel at the top
7. Attach vacuum line to the vacuum pump. -3-
Engine wiring harness and vacuum line
8. Fit engine wiring harness with rubber sleeve (seal) into the plenum panel wall. -2-
9. Fit heater and coolant hoses on both sides of the centre plenum panel wall at the top.
Clamped hoses
9.1. The locking clip on the couplings must engage with an audible click at the correct position. -1-. Remove hose clamps.
Disconnected hoses
10. Engage relay box in the strut. -1-
Relay box on strut
11. Fit left plenum panel wall.
11.1. Move plenum panel wall into installation position.
11.2. Fit fastening screws on the left plenum panel wall. => Mounting for left plenum panel wall at the side
Mounting for left plenum panel wall at the side
11.3. Secure wiring harness to the plenum panel wall. -3-
11.4. Connect cable plugs for both sensors -1 and 2-. Carefully plug the cable plug on the spring strut -1 - straight in (risk of breakage).
Left-hand side plenum panel wall at the periphery
12. Fit right plenum panel wall.
12.1. Move plenum panel wall into installation position.
12.2. Connect cable plugs for both sensors. -1 and 2- Carefully plug the cable plug -1 - on the spring strut straight in (risk of breakage).
Right-hand side plenum panel wall at the periphery
12.3. Route and secure the wiring harness at the plenum panel wall. -3-
12.4. Fit fastening screws on the right plenum panel wall. => Mounting for right plenum panel wall at the side
Mounting for right plenum panel wall at the side
13. Fit the two foam pads at the sides of the wing. => Two foam pads at the sides
Two foam pads at the sides
Subsequent work
1. Fit wiper linkage for front wiper. -> 921919 Removing and installing wiper linkage
2. Install cowl panel cover. -> 508719 Removing and installing cowl panel cover - section on "Installing" Service and Repair
3. Fit plenum panel cover. -> 852219 Removing and installing plenum panel cover 852219 Removing and installing plenum panel cover
4. Check the engine coolant level and top up if necessary. Check again after a test drive and top up as required.