Disassembling Pistons
CAUTION:
Engine damage if piston rings overstretched!
→ Do not overstretch piston rings with piston ring pliers. Spread the piston ring until it just fits over the piston.
Information
- If reusing a piston, do not remove combustion residues on the piston crown are mechanically!
- Piston-ring set; oil with engine oil; TOP marking facing upwards; oil scraper ring down; ring gaps offset by 120°
- Piston; different on naturally aspirated and turbo engines; combustion chamber recess facing center of engine; left and right different; direction of travel arrow in direction of travel
- Piston-pin circlip (positioned at 6 o'clock or 11 o'clock)
- Piston pin; oil
- Connecting rod
- Connecting rod bolt; replace as it must be tightened in the plastic area; oil screw
- Connecting rod bearing shells; oil with engine oil
- View A (identification area for connecting-rod number; fit connecting rod with identification area facing exhaust side; markings on rod and cap must be on the same side)
- View B (fit bearing shells flush and press in by hand)
- View C (fit bearing shells flush and press in by hand)
- Marking for dimension group (just one permitted per engine, in this case x)
- Porsche short numeric code without main or middle number
- Short numeric code (supplier)
- Marking area for weight group (just one permitted per engine, + or -)
- Cylinder bank identification (V6 1-3 and 4-6) (V8 1-4 and 5-8)
- Barcode 128 (short numeric code without main group or weight group)
- Arrow marking in direction of travel
- Identification for dimension group
- Arrow marking in direction of travel
- Inspection stamp (supplier)
- Arrow marking in direction of travel
- Porsche short numeric code without main or middle number
- Short numeric code (supplier)
- Cylinder bank identification (V8 1-4 and 5-8)
- Marking area for weight group (just one permitted per engine, + or -)
- Barcode 128 (short numeric code without main group or weight group)
- Arrow marking in direction of travel
- Marking for dimension group (just one permitted per engine, in this case x)
- Marking area for weight group (just one permitted per engine, + or -)
- Inspection stamp (supplier)
Information
- When disassembling the piston/connecting rod unit, note or mark the position, relationship to cylinder and installation position using a waterproof felt tip pen.
- Secure piston on retaining device 9597 (→ Piston on retaining device ).
- Remove both piston-pin circlips using a small screwdriver. To do this, guide the screwdriver through the small cut-out and carefully lever out the piston-pin circlip → Levering out piston-pin circlips with a small screwdriver .
- Insert piston into the retaining device 9597 (leave space below for the piston pins) and drive out piston pins using a suitable pressure piece. → Piston pin with plunger
- Remove connecting rod from the piston and place to one side.
Information
- Compression rings and oil scraper rings are installed and removed differently.
- Remove piston rings.
- 5.1. Place the piston on a clean surface and look for the gaps in the piston rings.
- 5.2. Remove the piston rings, starting at the piston crown. To do this, move the middle point of piston ring pliers Gr. 1 Nr.58 into the gap in the relevant ring. The holding arms of the piston ring pliers should clasp the piston ring from above → Piston ring pliers on piston ring . Only open the piston ring as much as is needed to remove the piston ring from the groove. Do not overstretch it!
- 5.3. Relieve the piston ring pliers and remove the piston ring from the pliers.
- 5.4. Remove the two-piece oil scraper ring as follows: First, remove the outer ring by hand by carefully prying it away from the piston. Then remove the inner oil scraper spring in the same way.