Porshe 911 (997). Manual - part 25

cover for dust protection
when fitting the engine

commercially
available tool

NR.165

universal piston ring
restraining strap, 75 - 125
mm

commercially
available tool

NR.55

piston ring pliers Gr. 1

commercially
available tool

NR.58

Removing pistons, preliminary work

Removing pistons, preliminary work

1. Disassemble engine to crankcase → 100137 Disassembling and assembling engine -

"Disassembling" section.

Removing pistons

Diagnostic system: reading out fault memory and activating systems

 Removing pistons, preliminary work

257

Removing pistons

ATTENTION

Risk of damage due to particles of dirt.

Oil bores/oil ducts can become blocked up.

• 

→ When working on the engine, absolute cleanliness is essential.

→ Lay removed engine parts on a clean base and cover them without fail.

→ Use the cover for dust protection when fitting the engine NR.165 on the engine assembly support.

Note

Fix the gear carrier for removing the pistons with two auxiliary screws to crankcase half 1-3.

• 

Note

Mark pistons in installation position before removal. Combustion residues (carbon desposits) can be
removed with a brass brush.

• 

Hard to remove residues can be removed in the ultrasound bath following disassembly.

• 

1. Unscrew inner Torx screws with O-ring (M9 x 94 inside and M9 x 84 outside) for gear carrier -arrows-

on crankcase half 1-3.

Diagnostic system: reading out fault memory and activating systems

Removing pistons

258

2. Unscrew inner Torx screw with O-ring M9 x 140 for gear carrier -arrow- on crankcase half 4-6.

3. Turn crankcase at assembly support until crankcase half 4-6 stands vertically upwards.

Coated screws for cross bolt connection

4. Unscrew four coated M6 x 35 Torx screws -1- on crankcase half 4-6 on flywheel side. Replace

screws during assembly.

5. Unscrew 20 remaining M6 x 35 Torx screws in the crankcase cross bolt connection.

Mount for crankcase half 4-6 on engine support

6. Unscrew the star screw that fixes crankcase half 4-6 to the engine support -arrow- .

Diagnostic system: reading out fault memory and activating systems

Removing pistons

259

Separating the crankcase half

7. Tap the crankcase halves gently with a plastic hammer. Carefully lever the various cast lugs with a

screwdriver to separate the crankcase halves from one another.

Levering off crankcase half 4-6

ATTENTION

Crankcase half 4-6 incorrectly levered off

Damage to pistons, piston rings

• 

→ Lever off crankcase half 4-6 only with the help of a second person.

8. Carefully lever off crankcase half 4-6 with the help of a second person to avoid damaging the pistons (e.g.

by tilting). Remove old shaft seals.

Auxiliary screws for securing gear carrier

9. For the following steps, fasten the gear carrier to crankcase housing half 1-3 with two cylinder-head

screws using spacer sleeves 9613. → Tightening torque: 15 ftlb.

Removing pistons, side 4-6

Diagnostic system: reading out fault memory and activating systems

Removing pistons

260