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Thoroughly Change Engine Oil (M278)

Brand: Mercedes-Benz

Model: S550 4Matic

​Chassis: W221

Engine: M278

Transmission: 722.9

Project: Maintenance

Labor: 1 hour

change engine oil


Replacing engine oil and the filter is routine maintenance every 1 year or 10,000 miles by the Mercedes-Benz maintenance booklet requires. There are two ways to discharge the used oil, extraction, or drain. In the Mercedes-Benz maintenance manual (WIS): For the M278 engine, the used oil is discharged by the extracting unit, in order to improve the work efficiency of the workshop. For the AMG engine M157, the same structure as M278 is required to drain the oil from the oil pan. After comparing the two methods, there can be filled with 8.5 liters of new engine oil as required by the booklet with drain used oil. For extraction of used oil, only 7.5 liters of new engine oil can be filled. I think this is why the M157 engine requires drain used oil from the oil pan. I chose to drain the used oil, even though it will take a little longer.


Engine Oil: Mobil 1 Synthetic, 0w-40,8.5 liters

Filter: Purflux (A 276 180 00 09) (up to engine serial number 30-021065)

Hengst (A 278 180 00 09) (after engine serial number 30-021065)

Check engine serial number

Crush Washer: 14mm (N 007603 014106)


Step 1 Left Vehicle

Lift Vehicle with floor jack and jack stands or two-post lift


2.1 Jack front vehicle at front central jack point;

2.2 Support vehicle at front side jack points with jack stands;

2.3 Jack rear vehicle at rear central jack point, if w/o rear central jack point, jack at the bottom of differential shell which  fixed at subframe carrier directly;

2.4 Support vehicle at rear side jack points with jack stands.

Step 2  Recording the Maintenance Information to OBD

Connect MB diagnosis unit


2.1 Connect the connector of OBD at the vehicle;

2.2 Connect the connector of LAN at the computer;

2.3 Start the XENTRY;

2.4 Confirm the performance of maintenance.

Step 3 Remove Bottom Engine Cover

Remove bottom engine cover to expose the oil pan 


3.1 Unscrew 8 bolts to remove the 2nd of the bottom cover

Step 4 Drain Out Used Oil


4.1 Remove the drain plug of the oil pan