Great video, thanks for posting this. Just did my 2018 GLC300, same W205 engine as the C300. took me about an hour and that included a break to wander the internet to find a confirming reference for the torque spec. I used 23 Nm for the plugs and 10Nm for the ignition coil bolts (30 torx). I used NGK 90654 SILZKFR8E7S - premium laser iridium spark plugs. As others have mentioned, the plug needs to be indexed which means the orientation of the spark plug as it sits in the engine is critical to engine health. This NGK plug was a perfect replacement of the OEM plug, with the same alignment of threads. This 4 cylinder 2.0 L turbo is not the smoothest Mercedes engine but changing the plugs made a notable improvement. Note: this engine has 1 plug per cylinder.
I also found one at autozone but it was short about 1/4 inch, went to O'Reilly and found a 14mm socket that was perfect but i had to add a piece of hose, but it works good
When ever the car requires, like in the instrument panel, it will call for service, but personally I look at the oil, and if it's to dark, I replace it, because the car has a turbo and it burns the oil
Nick, the dealer recommended mine be changed at 60k. They wanted $1300 to change the plugs and the air filter. I thought he was kidding, but he said they were special iridium tip plugs from Germany. I told him no thanks, I’ll take care of it myself. $105 dollars for the plugs and the filter and 20 minutes of my time and that included cleaning the engine compartment. $1200 bucks saved!
@@phoenixblack1220 mine asked $600 to change plugs only. only 20k on the c450 amg. dealer said the cost was mostly for labor. said something about removing some part to get at the plugs or whatever.
@juniorg6858 You need a spark plug gage, and on one end of the spark plug, you measure the gap between inside and outside electrodes. The outside electrode looks like a hook, make sure not to damage inside electrode, to adjust the gap you move the outside electrode
