2006 Mercedes S-Class Owner's Manual - Page 295

Operation Engine compartment Coolant level The engine coolant is a mixture of water and anticorrosion/antifreeze. When checking the coolant level, the vehicle must be parked on level ground, and the engine must be cool. Warning! Using a rag, turn the cap slowly approximately one half turn to the left to release any excess pressure. Continue turning the cap to the left and remove it. Using a rag, slowly open the cap approximately 1/2 turn to relieve excess pressure. If opened immediately, scalding hot fluid and steam will be blown out under pressure. Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn if it comes into contact with hot engine parts. ! S 600 and S 65 AMG: Only open the cap on coolant expansion tank 1. Never open the cap between the charge-air coolers. Otherwise, the engine could be damaged. The coolant level is correct if the level for cold coolant: reaches the white marking (plastic bridge) inside the coolant expansion tank. for warm coolant: is approximately 0.6 in (1.5 cm) higher Add coolant as required. G In order to avoid any possibly serious burns: Use extreme caution when opening the hood if there are any signs of steam or coolant leaking from the cooling system, or if the coolant temperature gauge indicates that the coolant is overheated. Do not remove pressure cap on coolant reservoir if coolant temperature is above 158°F (70°C). Allow engine to cool down before removing cap. The coolant reservoir contains hot fluid and is under pressure. The coolant expansion tank is located on the passenger side of the engine compartment. 1 Coolant expansion tank Replace and tighten cap. For more information on coolant, see "Coolants" ( page 439). 294