How to Remove the Oil Filter Housing on a W123


1. Turn the W123 on and warm the engine to its normal operating temperature. Turn off the engine. Elevate the vehicle at the front end using a floor jack or vehicle ramps. Put on the parking brake and place axle stands under the jacking points behind the front wheels. Also place a cinder block behind each of the back wheels to prevent the car from rolling.
2. Find the oil drain plug located under the vehicle and place an empty drain pan under the plug. Remove the drain plug slowly, pulling the plug straight down. Use a 13 mm socket and socket wrench to loosen the plug. Let the oil fully drain from the tank into the oil pan. Use extreme caution because the oil will be hot.
3. Lift the hood of the vehicle up and remove the filter cover by loosening the 13 mm bolt located on the cover top. Pull the cover off from the filter housing. Detach the rubber gasket and washer from the filter cover. Replace the new gasket and washer that is supplied with the new filter.
4. Take the oil filter from its housing. Use a pair of rubber gloves to do this as the filter will contain hot oil. Take the filter off slowly to allow the oil time to drip out of the filter into the bottom collector. Place the new filter into the housing down straight so it settles correctly. Put the oil filter cover back on and tighten the 13 mm bolt using a socket wrench. Close the hood.
5. Look under the W123 to see if the oil has stopped dripping into the pan. Once all the oil is drained, fit the plug back onto the vehicle. Lower the vehicle to the ground, removing it from the jack or ramps. Add new oil to the engine as recommended by the user's manual. Check the oil level with the dip stick. Wipe the stick off and check the level again until enough oil is added.