DIY: M112 Spark Plug R&R
For some reason the plugs I put in had connectors ever so slightly larger than the ones I took out. Both were OEM. I ended up taking one of the new plugs out and using it to force the connectors open on all the plug wires while I had them out and in hand. Boot lubricant also helps.
Good luck!
Last edited by ohlord; Feb 28, 2011 at 02:54 AM.
Went to the dealer and bought some spark plugs for my '04 C320 Sport with my $100 coupon and they gave me plugs based off of my VIN. The part number for the plugs is:
A 004 159 50 03 64
Now my question, these are obviously a different part number and the tips are gold instead of the silver/platinum. A google search yields little to nothing on this part number, rmeuropean does not have it listed for my model, and parts.com, and trademotion of Ft. Lauderdale are dead ends. Are these plugs safe to use or should I consider going back and trying to exchange them? They have a Mercedes logo on the plugs themselves and nowhere on the plug or the boxes does it say NGK or Bosch, etc.
Any help is appreciated. Thanks.
Went to the dealer and bought some spark plugs for my '04 C320 Sport with my $100 coupon and they gave me plugs based off of my VIN. The part number for the plugs is:
A 004 159 50 03 64
Now my question, these are obviously a different part number and the tips are gold instead of the silver/platinum. A google search yields little to nothing on this part number, rmeuropean does not have it listed for my model, and parts.com, and trademotion of Ft. Lauderdale are dead ends. Are these plugs safe to use or should I consider going back and trying to exchange them? They have a Mercedes logo on the plugs themselves and nowhere on the plug or the boxes does it say NGK or Bosch, etc.
Any help is appreciated. Thanks.
Nevertheless, MB’s rebranded and repackaged plugs typically have the manufacturer’s PN embossed on their shell.
Post that information and I’ll verify you’ve received proper plugs.
The M112 calls for a 14mm thread, 19mm (3/4") reach, 5/8" hex, gasket seat resistor plug.
Heat range differs depending upon application (e.g., supercharged).


M113 Kompressor/M271 shown
The Best of Mercedes & AMG
Nevertheless, MB’s rebranded and repackaged plugs typically have the manufacturer’s PN embossed on their shell.
Post that information and I’ll verify you’ve received proper plugs.
The M112 calls for a 14mm thread, 19mm (3/4") reach, 5/8" hex, gasket seat resistor plug.
Heat range differs depending upon application (e.g., supercharged).


M113 Kompressor/M271 shown
On the silver rim just above the threads: OF 073
The Box reads:
A 004 159 50 03 64
Maid in USA 15415227 14.09.10
Thanks for any help Splinter, it's much appreciated.



CHRYSLER CROSSFIRE 2008-2004
MERCEDES-BENZ C32 AMG 2004-2003
SLK230 2004-2003
SLK32 AMG 2004-2003
Mercedes does respecify and supersede parts all the time, so it is possibly OK. You need to assume the parts Bob typed in the VIN correctly.
I also find it interesting that the box says "Maid (hmm, cleans the windows too?) in USA" because there is a large plant near Shanghai that makes similar plugs and some counterfeiters print other peoples logo's on them.
The "maid" was actually a typo on my part. The box reads correctly. Nice catch!

(maybe a mod wants to add it to the 1st post)Autozone parts: $146... (i got extra spark plugs)
Time: 5 hours or so...
I had never even changed the oil in my car before reading this post. I read this and got my supplies, disconnected the negative connector from the battery (not both), replaced 6 spark plugs, let it sit for a week, replaced the other 6, reconnected the battery (got a spark when i reconnected) turned the key and everything was good to go. Just needed to set the time. No Issues. That led to me replacing the wipers, cabin filter, headlight which saves me over $750... so far. Fuses next. Thank you all for empowering me to be handy with car repairs and giving me the confidence to fix the rest of these little things myself and save hundreds of dollars along the way. And you've been great for my social life.
My chick is like "That's so sexy!". #Winning!
Autozone parts: $146... (i got extra spark plugs)
Time: 5 hours or so...
I had never even changed the oil in my car before reading this post. I read this and got my supplies, disconnected the negative connector from the battery (not both), replaced 6 spark plugs, let it sit for a week, replaced the other 6, reconnected the battery (got a spark when i reconnected) turned the key and everything was good to go. Just needed to set the time. No Issues. That led to me replacing the wipers, cabin filter, headlight which saves me over $750... so far. Fuses next. Thank you all for empowering me to be handy with car repairs and giving me the confidence to fix the rest of these little things myself and save hundreds of dollars along the way. And you've been great for my social life.
My chick is like "That's so sexy!". #Winning!Thanks
I tried for a solid hour with tons of different methods, even putting a small wrench into the box end of the 17mm offset wrench and trying to leverage that with my arm. Any harder and I would have broken my arm. Am I missing something here? I even put a bunch of dielectric grease on the inside of the boot and on the spark plug itself!
Any help/tips are appreciated. I've got no working car now! Thanks









