Spark plugs torque spec for GLS 450 (M256 engine)
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2022 GLS 450 (X167)
Spark plugs torque spec for GLS 450 (M256 engine)
Hello, can anyone access any service information on the spark plugs torque spec for GLS450 (the six-cylinder, M256 engine)?
I have changed plugs on any of my vehicles in the past and have generic information about what it could be, but I remember some of the Mercedes had indexing plugs and required the proper torque. I wanted to follow the service specs for those.
Thank you!
I have changed plugs on any of my vehicles in the past and have generic information about what it could be, but I remember some of the Mercedes had indexing plugs and required the proper torque. I wanted to follow the service specs for those.
Thank you!
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From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
When changing your spark plugs yourself, you may run into deteriorated plug wires.
My dealer found them at my 40k checkup and warrantied them.
Too much insistance on biodegradable parts by Germany, IMO.
My dealer found them at my 40k checkup and warrantied them.
Too much insistance on biodegradable parts by Germany, IMO.
Member
Joined: Mar 2025
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From: Los Angeles
2020 E53 AMG Sedan
yes after speaking to a couple of dealers i found one who will do it for $900 and will probably go that route since i'm still under warranty if they happen upon a degraded harness. the guy did say it tended to be more common on the GLS but that it was relatively widespread
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2017 GLE350 4MATIC
Hello, can anyone access any service information on the spark plugs torque spec for GLS450 (the six-cylinder, M256 engine)?
I have changed plugs on any of my vehicles in the past and have generic information about what it could be, but I remember some of the Mercedes had indexing plugs and required the proper torque. I wanted to follow the service specs for those.
Thank you!
I have changed plugs on any of my vehicles in the past and have generic information about what it could be, but I remember some of the Mercedes had indexing plugs and required the proper torque. I wanted to follow the service specs for those.
Thank you!
Indexing is addressed automatically by buying and installing dealer-purchased spark plugs and tightening to 23Nm.
Member
Joined: Mar 2025
Posts: 149
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From: Los Angeles
2020 E53 AMG Sedan
yes after speaking to a couple of dealers i found one who will do it for $900 and will probably go that route since i'm still under warranty if they happen upon a degraded harness. the guy did say it tended to be more common on the GLS but that it was relatively widespread
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Joined: Oct 2009
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From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
slight update - found a different dealer who will do it for less than $600. i had it in recently for diff/xfer case service and they did a visual on the harness which looked fine (but they said usually it fails when you start removing the wires) so i'm going to wait a few months until i'm almost out of warranty. that way the harness has more time to start looking like crap and if it fails when they replace the plugs it should be covered
My dealer found the wires to be questionable at my 40,000 mile b service, and replaced them at that time, under warranty.
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Member
Joined: Mar 2025
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From: Los Angeles
2020 E53 AMG Sedan
any idea if the new harness is any better than the old one? obviously will just happen again if they haven't changed anything
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MBWorld Fanatic!
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From: Colorado
'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
that's helpful to know - i'm at 33k miles so still kind of "early" on the mileage but at 5 years. just don't want to get stuck replacing the harness especially since it's such a known issue and defect
any idea if the new harness is any better than the old one? obviously will just happen again if they haven't changed anything
any idea if the new harness is any better than the old one? obviously will just happen again if they haven't changed anything
