Remove/Install Coolant Thermostat - AR20.10-P-2461MNI

Engine 177 in model 290 

Shown on engine 177.9 

Fig 1: Coolant Thermostat Components Location - Engine 177.9 In Model 290

Courtesy of MERCEDES-BENZ USA

Shown on engine 177.9 

Courtesy of MERCEDES-BENZ USA

	Risk of injury  to skin and eyes suffering scalding from contact with hot coolant spray. Risk of poisoning  from swallowing coolant.	Do not open cooling system unless coolant temperature is below 90°C. Open cap slowly and release the overpressure. Do not pour coolant into beverage containers. Wear protective gloves, protective clothing and safety glasses.	AS20.00-Z-0001-01A
	Risk of injury  . Skin or eye injuries may result when handling hot or glowing objects.	Wear protective gloves, protective clothing and safety glasses, if necessary.	AS00.00-Z-0002-01A
	Risk of injury  caused by scraping or cutting body parts on sharp vehicle parts	Always wear protective gloves when working on or near sharp and non-deburred vehicle parts. Deburr repair panels.	AS00.00-Z-0017-01A
Notice	Information on preventing damage to electronic components due to electrostatic discharge		AH54.00-P-0001-01A
Notice	Notes on avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
Notice	Notes on coolant		AH20.00-P-2080-01KOA
	Notes on coolant level		AH20.00-P-1142-01CW
	Remove/install
1	Remove charge air coolers.	Engine 177.8 in model 290	AR09.41-P-6817LSE
		Engine 177.9 in model 290 : Only install upper engine cover and lower engine compartment paneling after the performing a leak test.	AR09.41-P-6817MNI
2	Release and disconnect electrical connector of coolant thermostat heating element (R48).
3	Remove coolant inlet fitting (3).	: Replace seal. Screw coolant outlet fitting/coolant connection to thermostat housing	*BA20.10-P-1005-01ZA
4	Remove screw (5).	Screw coolant outlet fitting/coolant connection to oil separator	*BA20.10-P-1010-01ZA
5	Remove screws (4) and remove coolant thermostat (7).	: Replace seal. Bolt, thermostat housing to crankcase	*BA20.10-P-1002-01ZA
6	Remove screws (6) and remove coolant connection.	Only when replacing coolant thermostat (7). : Replace seal. Screw, coolant outlet fitting/coolant connection to thermostat housing	*BA20.10-P-1005-01ZA
7	Install in the reverse order.