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My local MB dealer did some service on our C450 and recommended a bunch of things to be replaced including the spark plugs. As I understand it there are two plugs per cylinder, so there are 12 in total. What I was surprised to see was that they were recommending two different part numbers for the plugs. They suggested (6x) 004-159-69-03 and (4x) 270-159-06-00 (I assume this 4x was a mistake and they meant 6x).
So the question is.. Do these engines really use two different plugs per cylinder? I've spent a bit more time that I care to admit searching Google about this and haven't found anything. I suppose I could call the dealer and ask, but figured I may as well start here.
Thank you for your quick reply. It is definitely strange that my dealer put the old part number on the quote at all then. Anyway, that definitely helps and now I can confidently place this parts order. 👍
Only thing i can think of is a dumb parts advisor or they want to get rid of the old plugs which they're probably sitting on.. There is a cost difference between the two.
i wouldnt want the A004.159.69.03 to be installed. The part number change was from over a year ago now.. What physically change on the spark plug, that i do not know.
I'm in Delaware. The story gets a bit strange as I search around:
AutohausAZ says 004-159-69-03 fits my car, but says the 270-159-06-00 doesn't.
FCP Euro lists an NGK part when I search for 004-159-69-03, but doesn't have anything for 270-159-06-00. It says the NGK is compatible.
ECS Tuning doesn't list 004-159-69-03 in their database at all any more and instead redirects to 270-159-06-00, which it says isn't compatible.
I really don't know my way around Mercedes parts yet. With BMW I just go to RealOEM and I see all parts for my cars based on VIN.
The original part number are plugs by NGK , the newer is a Bosch plug and was updated around 2018. Fyi the Bosch plugs are hotter than the NGK , I bought the original NGK plugs outside of the dealership (FCP Euro) and stuck with that since I'm tuned.
Last edited by BayAreaAMG; Dec 13, 2022 at 01:25 PM.
For sure only one plug per cylinder on our motors, and i believe all of the newer MB motors. The 2 plug per cyl was from an older era of MB motors.
Did you give the dealer your VIN to look up the part # with?
As for the Bosch vs NGK this is the first ive seen this and it has me questioning which is a better choice.
From NGK site they list 2 options - SILZKFR8G7S (96427) and SILZKFR8D7S (95875) (NGK site says "sell out and order G configuration" on the D style description)
Bosch lists EVO 96347.
Both copper core, iridium top with same thread and hex sizes.
As mentioned, the Bosch has a 2 range hotter plug than the NGK. This is not typically what you want for boosted applications and performance.
I would think lower resistance is also preferred as it would mean more power to the electrode and less wear on the boot/coil.
Not sure how an extra mm of reach would effect cooling and flame front.
The original NGK that I pulled from the engine were the SILZKFR8D7S (NGK-95875). The Bosch plug that the dealership sold me almost 2 years ago was BOSCH V6S113328 (BOSCH 7434)
Last edited by BayAreaAMG; Dec 14, 2022 at 02:08 PM.
Thank you all for the great answers. I honestly didn’t expect to go quite this far down a rabbit hole.
Originally Posted by MatthewJ
For sure only one plug per cylinder on our motors, and i believe all of the newer MB motors. The 2 plug per cyl was from an older era of MB motors.
Did you give the dealer your VIN to look up the part # with?
Yes, the car was in for the service B and MB suggested a bunch of other work to be done, so they definitely had the correct vin when they gave me the parts list. Since my son is a mechanic I offered him the same money Mercedes was asking and he jumped at it. I was just trying to help track down the parts.
It seems there was something wrong with the original NGKs if both they and Mercedes switched away from them. Right or wrong I ended up getting the original NGK “D” 95875. Hopefully they will be ok. It may have just been better to get the Bosch, but I imagine I won’t notice the difference.
Last edited by ThrowoutBearing; Dec 17, 2022 at 12:09 AM.
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