2009 Mercedes SL-Class Owner's Manual - Page 305

Practical hints What to do if ... Problem Ì The red coolant temperature warning lamp comes on when the engine is running. Possible cause/consequence There is insufficient coolant in the reservoir. If this warning lamp comes on frequently, there is a leak in the cooling system. If the coolant level is correct, the electric radiator fan may be broken. Suggested solutions X X X X Immediately add coolant to prevent engine from overheating (Y page 207). Have the cooling system checked. If the coolant temperature is below 248‡ (120†), you can continue driving to the nearest authorized Mercedes-Benz Center. Avoid high engine loads (e.g. driving uphill) and stop-and-go driving. Stop in a safe location as soon as possible and allow the engine and coolant to cool down. Ì The red coolant tempera- The coolant temperature has ture warning lamp comes exceeded 248‡ (120†). on when the engine is running and you hear a warning sound. X G Warning! Driving when your engine is overheated can cause some fluids which may have leaked into the engine compartment to catch fire. You could be seriously burned. Steam from an overheated engine can cause serious burns which can occur just by opening the engine hood. Stay away from the engine if you see or hear steam coming from it. Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the vehicle and do not stand near the vehicle until the engine has cooled down. ! The engine should not be operated with the coolant temperature above 248‡ (120†). Doing so may cause serious damage which is not covered by the MercedesBenz Limited Warranty. Z 303