Spark Plug Issue

Mar 19, 2015 | 01:13 PM

W204Man

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Senior Member

Joined: Aug 2012

Posts: 341

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08 C-Class (sold)

Spark Plug Issue

So the other week I installed new spark plugs. They were Bosch YR7MPP33, I check multiple places and I was told I needed Bosch YR7MPP33. After I installed them my engine started stuttering/knocking. I checked my old spark plugs and they are Bosch Y7MPP33.
What is the difference between the two? What spark plugs are y'all running in your 08 c300?

Last edited by W204Man; Mar 19, 2015 at 01:19 PM.

Mar 19, 2015 | 01:35 PM

Antique-Ace

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Joined: Feb 2015

Posts: 143

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From: Central Kentucky

2014 CLS550-4M, 2013 C350-4M Coupe

MB specs call for the Y7MPP33 (without the "R") but it should not make a difference IMO. The "R" in YR7MPP33 stands for "resistor", which Bosch says is installed to eliminate interference with electronics like AM radio signals.
Are you sure all your coil packs are installed back correctly and none were damaged?

I just found this thread that has some interesting info on YR7MPP33 vs Y7MPP33 spark plugs in MB engines.
http://www.peachparts.com/shopforum/...sch-plugs.html

Last edited by Antique-Ace; Mar 19, 2015 at 01:46 PM. Reason: Added additional info.

Mar 19, 2015 | 03:13 PM

louiet3

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Joined: Mar 2009

Posts: 295

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From: Brentwood,CA

2009 C300 Sport Palladium Silver & 2012 GLK350 4matic Black

2009 C300.

Had the spark plugs replaced by local indie shop owned by an MB master mechanic. The invoice has YR 7 MPP33 as part number.

Sep 1, 2023 | 12:42 AM

Bobbyjamesjr

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Joined: Sep 2023

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2011 c300 sport

My c300 sport takes NGK Mercedes dealership

The mechanic at Mercedes told me they come from the manufacture with NGK

Sep 2, 2023 | 01:20 PM

TimC300

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From: MA Coast

W204 2010 C300 4matic Sport M272

My owners manual in the glove box says Bosch Y 7 MPP33.

Sep 2, 2023 | 01:58 PM

Odd Piggy

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2021 GLB250 FWD, 2023 GLA250 FWD, 2013 C250, 2015 GLK350, 2005 ML350SE, 2003 E320

Quote:

Originally Posted by Bobbyjamesjr

The mechanic at Mercedes told me they come from the manufacture with NGK

From personal experience, Mercedes factory plugs can be either Bosch or NGK. Had 2 cars with M112 engines. One had Bosch from the factory and the other, to my surprise, had NGK. Some engines, like the early M276, where spark plugs were developed specifically for that application with the vendor, will have only one brand available until the design is released to the aftermarket.

Sep 3, 2023 | 09:51 AM

JettaRed

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From: Maryland

2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)

Quote:

Originally Posted by Odd Piggy

And with Direct Injection engines, I would ONLY use what is specified and install the exactly as instructed (i.e., to the precise torque specifications).