2017 GLS 450 Spark Plug Install
Thread Starter
Newbie
Joined: Oct 2007
Posts: 1
Likes: 1
C280
2017 GLS 450 Spark Plug Install
Tried doing a spark plug replacement with the help of a friend and removing the spark plug boot was a real pita. What spark plug boot removal tool are you using to remove your spark plug on a GLS 450?
Does anyone have detailed tutorial to remove spark plugs on a GLS 450 so we can do things quicker. We only completed the (3) spark plugs on the driver side and that took us 5 hrs.
Any help would be greatly appreciated.
Thanks in advance.
Regards, Jose
Does anyone have detailed tutorial to remove spark plugs on a GLS 450 so we can do things quicker. We only completed the (3) spark plugs on the driver side and that took us 5 hrs.
Any help would be greatly appreciated.
Thanks in advance.
Regards, Jose
Out Of Control!!
Joined: Sep 2018
Posts: 14,692
Likes: 4,584
From: unbegrenzt
2017 GLE350 4MATIC
Jose, you have the twin turbo 3.0L V6 correct?
Look at Senior Leigh’s video on YouTube for the M276 DE35 spark plug replacement.
There will be differences in removing the intake components for your engine, but because the turbos on your engine are not “hot vee” the spark plugs should come out in a similar fashion.
Senior Leigh uses a curved jaw heavy needle nose plier to pull the coil boots. I saw one at harbor freight yesterday so they can’t be too hard to find.
It doesn’t seem to me like any specific brand of tool is needed to do this job, with the exception of the intake duct Click Clamp pliers, which many people recommend to use Knipex. I have the Knipex pliers and they are very good.
Look at Senior Leigh’s video on YouTube for the M276 DE35 spark plug replacement.
There will be differences in removing the intake components for your engine, but because the turbos on your engine are not “hot vee” the spark plugs should come out in a similar fashion.
Senior Leigh uses a curved jaw heavy needle nose plier to pull the coil boots. I saw one at harbor freight yesterday so they can’t be too hard to find.
It doesn’t seem to me like any specific brand of tool is needed to do this job, with the exception of the intake duct Click Clamp pliers, which many people recommend to use Knipex. I have the Knipex pliers and they are very good.
Senior Member
Joined: Apr 2007
Posts: 311
Likes: 73
From: Richmond, Virginia USA
'12 E550, '10 ML350, '06 E350, '20 GLC300, '21 GLC300
I change mine out before 60K miles on every MB I've owned whether it was a 4, 6 or 8 cylinder. Never had problems with threads. I have had the boot rubber fail but that was over 180K miles & 9yrs old.
Junior Member
Joined: Nov 2021
Posts: 63
Likes: 16
2022 GLS 450 (X167)
2022, GLS 450
For the spark plugs on the inline six M256, there is only one thing you don't want to ignore, that is the torque spec on the plugs, which is 15 Nm or 11.25 lbs.ft
Those are small plugs, and the regulator 23Nm can strip. Gap is 0.026"
I needed to remove the turbo shroud, disconnect the gate arm, and remove the turbo air intake pipe. Just wanted to have space to work. Cilinder 6, close to the firewall, is the most difficult. A flex shaft extension might be helpful for the spark plugs.
And don't forget 15 Nm on the plugs.
For the spark plugs on the inline six M256, there is only one thing you don't want to ignore, that is the torque spec on the plugs, which is 15 Nm or 11.25 lbs.ft
Those are small plugs, and the regulator 23Nm can strip. Gap is 0.026"
I needed to remove the turbo shroud, disconnect the gate arm, and remove the turbo air intake pipe. Just wanted to have space to work. Cilinder 6, close to the firewall, is the most difficult. A flex shaft extension might be helpful for the spark plugs.
And don't forget 15 Nm on the plugs.
