top of page







Replacing Spark Plug

Brand: Mercedes-Benz

Model: E350

Chassis: W212

​Engine: M276 DE35

Transmission: 722.9

Project: Maintenance

​Labor: 2 hours



Replacing spark plus is regular maintenance. There is a requirement every 60k miles or 6 years to replace the spark plugs in the MB maintenance booklet. To naturally aspirated engine of M276 DE35, there is a step to remove the resonance intake manifold to reach the ignition coil in the WIS. But that must replace a set of expensive intake plenum gaskets with more labor. Removing the ECU may make more room to reach the concealed ignition coil and spark plugs. More detail below.

Replace Spark Plugs of 4th, 5th & 6th Cylinder

Step 1  Open The Engine Hood


1.1 Pull lever on left side of the footwell to unlock the engine hood. The engine hood jumps open; lift engine hood slightly if necessary;

1.2 Pull out handle and lift to open engine hood. (Windshield wiper arms must not be folded forward).

Step 2 Remove ECU (Important Step)


2.1 Remove front engine cover;

2.2 Remove electric connecter from ECU;

2.3 Remove ECU;

2.4 Remove wire harness from resonance intake manifold;

2.5 Unscrew the bracket of electric wire harness.

Step 3 Remove the Used Spark Plug of 6th Cylinder (The Most difficult One)


3.1 Detach connector of ignition coil;

3.2 Remove bolt of ignition coil;

3.3 Pull ignition coil upwards and remove;

3.4 Remove spark plug.

Step 4 Install the New Spark Plus of 6th Cylinder