Valve Spring: Service and Repair

11 34 715 Replacing All Valve Springs (N55)

Special tools required:







Necessary preliminary tasks:
- Remove cylinder head.
- Remove exhaust camshaft.
- Remove intermediate lever.
- Remove intake camshaft.
- Remove rocker arm.







Place cylinder head on special tool 11 9 000.
Align special tool 11 9 007 on particular combustion chamber.







Position special tool 11 9 007 on cylinder head.
Push locks (1 and 2) toward inside and preload via eccentric shaft.







Press down intake valve with special tool 11 8841.







Remove valve key (1) with a magnet.
Remove valve spring with spring cups.
If individual components are to be reused, they must be placed in neat order in special tool 11 4 481.







Press down discharge valve with special tool 11 8 842.







Remove valve key (1) with a magnet.
Remove valve spring with spring cups.
If individual components are to be reused, they must be placed in neat order in special tool 11 4 482.







IMPORTANT:
Incorrect assembly possible.
Incorrect installation will result in valve spring breakage.
Risk of mixing up the valve springs for the inlet and exhaust valves.

Valve springs are marked in colour (1).

Colors for intake valves:
- Green/blue
- Yellow/Blue

Colors for discharge valves:
- Green/white
- Yellow/white

Install the valve spring so that the larger diameter points to the lower spring cup.







Arrangement:
1. Valve
2. Valve stem seal with lower spring cup
3. Valve spring
4. Upper spring cup
5. Valve keys







Assemble engine.
Check function of Digital Engine Electronics; if necessary, readjust uniform mixture distribution.