Casting Port Covers (6 Cylinder Engine) (Mercedes-Benz C-Class W202)

The cast holes are located on the side of the engine block. They are connected to the coolant channels and are covered with metal caps. If the coolant freezes at low temperatures, the metal cap is pressed out. This prevents damage to the engine block. Leaky cast hole caps must be replaced.

1. Remove any parts of the unit that interfere with access to the appropriate casting cover.

2. Place a screwdriver or narrow chisel on the edge of the lid.



3. Carefully push the locking cap (121) in from one side until it turns 90°.



4. Pull out the turned cover using a pipe wrench.



5. Thoroughly clean the cast hole from deposits. The sealing surface (arrow) must be clean from deposits.



6. Cover the sealing surface with sealant (for example, Loctite N₂41 or Curil).



7. Drive in the new locking cap with a suitable pin. Allow the sealant to cure according to the manufacturer's instructions (about 45 min.).

8. Install the dismantled parts of the unit.

9. Fill with coolant.

10. Warm up the engine, check the coolant level and the tightness of the cast hole covers.