Replace Spark Plugs
Here a quick guide on how to replace Spark Plugs for 272/273 engines. The car I replaced it on was a 2008 C300 Luxury (also did it for a friend’s 08 ML350). It is recommended that you replace spark plugs every 5 years or 90k miles (whichever one comes first).
Required items
• 6 Spark plugs (I got NGK Laser Platinum PLKR7A 4288)
• Anti-Seize Thread Lubricant
• Torque wrench
• Wrench Extensions (multiple lengths)
• 5/8’ Spark Plug Socket: the only difference between a normal socket and spark plug is that the spark plug socket has a built in magnet that prevents the spark plug from falling back into the engine (I highly recommend getting it)
• T-30 Torx Bit Socket
• Flat Head Screwdriver
![Image]()
Procedure
1) Remove the air intakes and the engine covers. For the intakes, use the screw drive to push in the clips holding it to the grill assembly. The rest you can pull off (might need to put in some force if you haven’t opened in for a long time)
![Image]()
![Image]()
2) Using the T-30 Torx Bit Socket, remove the two screws that hold the wiring for the spark plug. After removing the screws, you will have to pull a little hard since it almost like a vacuum holding it in.
![Image]()
![Image]()
3) Using extensions and the spark plug socket reach into the engine bay and open the spark plug. They were a little stuck at first but after a few spins they come out easy.
![Image]()
4) Open the new spark plug and apply a little Anti-Seize Thread Lubricant to the threads. The small packet in the photo above lasted me all 6 spark plugs.
![Image]()
5) Insert the new spark plug into the socket and put it back into the engine. Tighten the spark plug. When tightening the spark plug, set the torque wrench to 20lb/ft.
6) Put the wiring harness back on top of the spark plug. Tighten the screws that hold in place. When tightening the screws for the harness, set the toque wrench to 10lb/ft.
7) Repeat steps 2-6 again for all the spark plugs
8) Go around to all the harness screws and double check they are tight to the right specifications (10 ft/lb).
9) Attach the engine cover back and install the air intakes.
10) Done!
This is an easy job for any DIY’er. I spent a total of an hour doing all of this. The dealer wanted $350.00 for this service and I did everything for around $90.00. The spark plugs were $13 each (factory oem).
Please feel to post your comment and questions and I can try to help answering them.
Thank you,
Here a quick guide on how to replace Spark Plugs for 272/273 engines. The car I replaced it on was a 2008 C300 Luxury (also did it for a friend’s 08 ML350). It is recommended that you replace spark plugs every 5 years or 90k miles (whichever one comes first).
Required items
• 6 Spark plugs (I got NGK Laser Platinum PLKR7A 4288)
• Anti-Seize Thread Lubricant
• Torque wrench
• Wrench Extensions (multiple lengths)
• 5/8’ Spark Plug Socket: the only difference between a normal socket and spark plug is that the spark plug socket has a built in magnet that prevents the spark plug from falling back into the engine (I highly recommend getting it)
• T-30 Torx Bit Socket
• Flat Head Screwdriver
Procedure
1) Remove the air intakes and the engine covers. For the intakes, use the screw drive to push in the clips holding it to the grill assembly. The rest you can pull off (might need to put in some force if you haven’t opened in for a long time)
2) Using the T-30 Torx Bit Socket, remove the two screws that hold the wiring for the spark plug. After removing the screws, you will have to pull a little hard since it almost like a vacuum holding it in.
3) Using extensions and the spark plug socket reach into the engine bay and open the spark plug. They were a little stuck at first but after a few spins they come out easy.
4) Open the new spark plug and apply a little Anti-Seize Thread Lubricant to the threads. The small packet in the photo above lasted me all 6 spark plugs.
5) Insert the new spark plug into the socket and put it back into the engine. Tighten the spark plug. When tightening the spark plug, set the torque wrench to 20lb/ft.
6) Put the wiring harness back on top of the spark plug. Tighten the screws that hold in place. When tightening the screws for the harness, set the toque wrench to 10lb/ft.
7) Repeat steps 2-6 again for all the spark plugs
8) Go around to all the harness screws and double check they are tight to the right specifications (10 ft/lb).
9) Attach the engine cover back and install the air intakes.
10) Done!
This is an easy job for any DIY’er. I spent a total of an hour doing all of this. The dealer wanted $350.00 for this service and I did everything for around $90.00. The spark plugs were $13 each (factory oem).
Please feel to post your comment and questions and I can try to help answering them.
Thank you,
