OEM spark plug C63s
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Joined: Dec 2025
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From: Keep it simple - keep it OEM
AMG C63s Coupe
OEM spark plug C63s
There are some threads here of loose plugs. 
Can you confirm this?
I checked the situation and asked why could this happend ?
- sloppy mechanic at service ?
- due to technical design of plug etc ?
Maybe bouth can cause it in my mind.
But i dont know for sure.
If you take a look to this spark plug ( OEM A0001590500 ?) you can see there is a copper ring to seal.
it looks „full metal“.
normaly this ring on plugs is build to squeeze (looks different).
I asked myself why not on this C63 plugs?
Aside from using the correct torque NM, what else could be done?
Tightening, loosening, tightening again?
Would that help a little bit ?
The reason (type of seal ring ) could be due to the information from Jimmy (picture below).
I think that full metal copper ring is nessesary for Positioning accurate to the millimeter and angle.
If that's the case, it would also mean
that the spark plug threads must always start in exactly the same position starting ( zylinderhead too) - or not ?
( Thats too much technical for me with the s-threads)
However but that tells me OEM spark plugs only to go for sure.
Can you confirm this?
I checked the situation and asked why could this happend ?
- sloppy mechanic at service ?
- due to technical design of plug etc ?
Maybe bouth can cause it in my mind.
But i dont know for sure.
If you take a look to this spark plug ( OEM A0001590500 ?) you can see there is a copper ring to seal.
it looks „full metal“.
normaly this ring on plugs is build to squeeze (looks different).
I asked myself why not on this C63 plugs?
Aside from using the correct torque NM, what else could be done?
Tightening, loosening, tightening again?
Would that help a little bit ?
The reason (type of seal ring ) could be due to the information from Jimmy (picture below).
I think that full metal copper ring is nessesary for Positioning accurate to the millimeter and angle.
If that's the case, it would also mean
that the spark plug threads must always start in exactly the same position starting ( zylinderhead too) - or not ?
( Thats too much technical for me with the s-threads)
However but that tells me OEM spark plugs only to go for sure.
Last edited by C63s_Jack; Feb 14, 2026 at 08:58 AM.
