2006 Mercedes CLK-Class Owner's Manual - Page 327

Operation Engine compartment Unscrew filler cap 1 from filler neck. Add engine oil as required. Be careful not to overfill with oil. Be careful not to spill any oil when adding. Avoid environmental damage caused by oil entering the ground or water. Transmission fluid level The transmission fluid level does not need to be checked. If you notice transmission fluid loss or gear shifting malfunctions, have an authorized Mercedes-Benz Center check the automatic transmission. ! CLK 350 1 Filler cap Excess oil must be siphoned or drained off. It could cause damage to the engine and catalytic converter not covered by the Mercedes-Benz Limited Warranty. Screw filler cap 1 back on filler neck. More information on engine oil can be found in the "Technical data" section ( page 479) and ( page 481). CLK 500, CLK 55 AMG 1 Filler cap 326