Removing and Installing Intake Valve
WM 156019 Removing and installing intake valve
Preliminary work
Preliminary work
1. Remove cylinder head.
2. Remove camshafts.
3. Take flat-base tappets out of the cylinder head and lay them on a clean surface, arranged according to cylinders and valves. Do not interchange components.
Information
Component overview
In the Turbo, the exhaust valve is fitted with internal and external valve springs and adapted concave washers (different to those shown in the figure below). The exhaust valve in the turbo engine has the same dimensions as the exhaust valve in the naturally aspirated engine; because of the sodium filling it is lighter however and when obtained as a spare part it features a colored dot to distinguish it. For further details, please see later chapter entitled "Valve dimensions".
Component overview of valves
1 - Valve collet (valve key)
2 - Top spring retainer
3 - Valve spring
4 - Spring plate, bottom
5 - Valve-stem seal
6 - Valve guide
7 - Intake positioning ring
8 - Intake valve
9 - Exhaust positioning ring
10 - Exhaust valve
Removing intake valve
Removing intake valve
Information:
Secure the cylinder head on a level surface, which allows easy access to the valves from underneath.
No valves should be hidden by the surface under the cylinder head.
The cylinder head fastening must not tip over when tools are used.
Information:
The illustrations show part of the cylinder head installed.
1. The spark plugs must be removed and the valve lock screwed in before the valves are removed. The valve lock prevents the valves from being opened while being pressed down. Alternatively, a rubber plate placed underneath helps if the cylinder head surface is smooth -2-.
Screwing in tool
Locking valves
2. Fit and adjust lever tool from the valve key assembly/disassembly tool for the Cayenne NR.54-1 set on the cylinder head. When doing so, ensure that the middle pipe is positioned centrally over the sparkplug recesses. The operating lever can be secured centrally or eccentrically. The fastening screws in the camshaft bearing caps in the front and rear bearing position are used to secure the tool brackets (figure shows fitted cylinder head). Use the white plastic pressure piece with the magnetic insert to remove the valve keys. The assembly must be performed as shown.
Removing tool setup for valve springs
3. Press the white plastic pressure piece with the magnetic insert against the top concave washer to remove the valve keys. The concave washer -2- and the valve keys -1- are attracted to the magnetic insert and release the valve (loosen valve keys with a screwdriver if they are stuck). Remove loose components (valve springs, top concave washer and valve keys). Repeat procedure as often as necessary for the affected valves (reposition tool accordingly).
Valve keys in tool
4. Remove valve lock. Push valve out at the combustion chamber side and remove it from the cylinder head.
Locking valves
Installing intake valve
Installing intake valve
Information:
Intake valves come in different sizes to exhaust valves. It is impossible to mix them up. Intake valves are identical in the naturally aspirated and turbo engines.
Exhaust valves in the turbo engine weigh less than exhaust valves in the naturally aspirated engine. They are marked with a green dot. Do not interchange them.
The valves cannot be touched up afterwards.
The valves can be ground using commercially available valve grinding paste.
1. Apply a small amount of valve grinding paste to the valve seat.
2. Oil the valve stem of a new valve and insert it into the valve guide from the combustion chamber. Push the valve in until it is seated securely in the valve seat of the cylinder head.
3. Grind in the valve using the commercially available valve grinding tool (with rubber suction cup) by means of rotary movements. To do this, hold the valve grinder between the palms of both hands and press against the valve seat with rotating movements.
Grinding the valve seat
Notice:
Valve grinding paste not removed
Risk of damage to sealing face on intake valve
- Remove all valve grinding paste fully after grinding.
4. Carry out the grinding operation for each valve that is replaced. Check for leaks using some fuel and installed spark plugs. The fuel must not escape through the valve seat. Carefully remove valve grinding paste.
5. Fit valve lock.
Locking valves
6. Replace valve-stem seals.
7. Fit valve springs, concave washer and valve keys. To do this, place valve springs (there are two in the exhaust valve in the turbo engine) on the bottom concave washer. Place top concave washer in position. Pull off the ring of the assembly tool -2- from the retaining springs -3- before inserting the valve keys. Position valve keys with the thin side facing upwards -1-.
Tool setup - valve keys
8. Insert valve keys into the assembly tool with the thin side facing upwards -1-. Ensure that the valve keys fit symmetrically and are inserted as far as they will go in the assembly tool. The retaining springs are free -2-.
Valve keys in assembly tool
9. Secure the valve keys by pushing up the ring. Check that the valve keys are aligned correctly -1-.
Valve keys in assembly tool
10. Insert valve key assembly tool in tool setup and position in front of the valve stem.
Valve key assembly
11. When assembling the valve keys, ensure that the assembly tool is inserted at the valve stem end -2- and is then pushed down (the tool remains secured when this is done -1- ). The valve keys click audibly into the valve grooves when the valve key assembly tool is pressed onto the valve. Check valve keys to ensure that they are installed correctly.
Valve key assembly in valve key grooves
Subsequent work
Subsequent work
1. Fit flat-based tappets. Do not interchange components.
2. Install camshafts.
3. Fit cylinder head.
Information
