M157 V8 spark plugs
- Thread starter Amg 007
- Start date
- Joined
- Nov 1, 2008
- Messages
- 19,387
- Location
- Bournemouth/Poole Dorset
- Car
- W210 E280 x2, w211 E55, W212 E63 biturbo, S204 C180K
Ive always used NGK plugs in the past but in my W212 E63 its under a service plan so the plugs were changed by the main dealer and assume they used the ones stamped with the MB logo.
Those are the plugs I would buy if I were changing them as I understand there is a problem with indexing other branded plugs. I'm unsure if there is any truth in that but I wouldn't take any chances.
So, get them from the dealership.
Those are the plugs I would buy if I were changing them as I understand there is a problem with indexing other branded plugs. I'm unsure if there is any truth in that but I wouldn't take any chances.
So, get them from the dealership.
ALFAitalia
MB Enthusiast
- Joined
- Feb 19, 2022
- Messages
- 6,788
- Location
- Bognor Regis
- Car
- 2010 Mercedes W212 E Class E350 CDI Sport, 2006 Mercedes W169 A Class A170.
Did they index ok? Quite important they do on these cars. Funny how its not on anything else that I've ever worked on though!
d.sloan
New Member
- Joined
- Jul 12, 2013
- Messages
- 5
- Location
- North Yorkshire
- Car
- Mercedes R231 SL63 amg, R129 SL, Aston Martin V8V
i hope this link works but it explains the criticality of using the correct plugs and compares the original MB plug to an NGK
- Joined
- Mar 11, 2013
- Messages
- 10,957
- Location
- South Bucks
- Car
- CLS63 SB, ML63, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
I've seen that before; it's mostly BS. Just looking at the two plugs, it is immediately obvious that they are not the same. Only an idiot would fit the wrong plug.
The indexing is a bit of a red herring; there is only ONE thread on the plug, and ONE thread in the cylinder head. Providing the plug is the correct one, and the tightening procedure is followed to the letter, the indexing will be correct.
Don't believe me? Buy a plug from MB; if it's an NGK plug, and it probably will be on more modern MB cars, there will be an NGK part number stamped around the thickest part of the plug below the insulator. If MB are cheaper, buy the plugs from them; if not, buy them from an aftermarket supplier of NGK plugs.
It may give you a warm fuzzy feeling if the MB logo is on the plug, but that logo and the MB box is all you are paying the extra for.
The indexing is a bit of a red herring; there is only ONE thread on the plug, and ONE thread in the cylinder head. Providing the plug is the correct one, and the tightening procedure is followed to the letter, the indexing will be correct.
Don't believe me? Buy a plug from MB; if it's an NGK plug, and it probably will be on more modern MB cars, there will be an NGK part number stamped around the thickest part of the plug below the insulator. If MB are cheaper, buy the plugs from them; if not, buy them from an aftermarket supplier of NGK plugs.
It may give you a warm fuzzy feeling if the MB logo is on the plug, but that logo and the MB box is all you are paying the extra for.
ALFAitalia
MB Enthusiast
- Joined
- Feb 19, 2022
- Messages
- 6,788
- Location
- Bognor Regis
- Car
- 2010 Mercedes W212 E Class E350 CDI Sport, 2006 Mercedes W169 A Class A170.
But its where the thread starts that might be different....resulting in a different angle. I'd have no issue fitting NGK (non MB marked) plugs.....but I'd be marking them to make sure that they finished in the correct position when at the correct torque. I have limited experience and have only fitted MB ones to one M157.....but based on threads on here, the Merc technical bulletin and threads on a US Merc forum I find it hard to believe that there is not a difference between the two plug versions.
- Joined
- Mar 11, 2013
- Messages
- 10,957
- Location
- South Bucks
- Car
- CLS63 SB, ML63, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
Same NGK part number = exactly the same plug, I'd say. NGK have a reputation to protect.
ALFAitalia
MB Enthusiast
- Joined
- Feb 19, 2022
- Messages
- 6,788
- Location
- Bognor Regis
- Car
- 2010 Mercedes W212 E Class E350 CDI Sport, 2006 Mercedes W169 A Class A170.
They would be....but maybe MB just specify theirs with the thread clocked right for them. If i fit a set of plus in most cars , at the correct torque they will finish in random positions.....I suspect that's because the threads start in different places around the plugs.....They will also all have the same part number. Just thinking out loud. I also don't believe that everyone who had said about this is stupid or being gullible buying MB plugs.
Edit....out of curiosity I just popped to my garage and looked at the old Bosch plugs I removed from my wifes A Class w169.....the starting point of the thread is different in two out of the four in relation to the electrode....all same part number.. Hmm.....so maybe there is something in this.
Edit....out of curiosity I just popped to my garage and looked at the old Bosch plugs I removed from my wifes A Class w169.....the starting point of the thread is different in two out of the four in relation to the electrode....all same part number.. Hmm.....so maybe there is something in this.
- Joined
- Mar 11, 2013
- Messages
- 10,957
- Location
- South Bucks
- Car
- CLS63 SB, ML63, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
That's Bosch, not NGK, and dating from before MB had secondary injectors in engines like the M157; the indexing is important in those, but it wasn't way back when. I rather suspect NGK are aware of the indexing issue.
NGK's own application chart specifies a particular plug for the M157; it's the same part number as you will find on the plug with the MB logo on it in the MB box. Do you think that either NGK check every plug with that part number that will go to MB to ensure that the thread starts in the right place, and only use those that are spot-on, or they manufacture special plugs with the same part number just for MB? I'd think their engineering tolerances are at least as good as MB's, if not better, and every plug is spot-on.
NGK's own application chart specifies a particular plug for the M157; it's the same part number as you will find on the plug with the MB logo on it in the MB box. Do you think that either NGK check every plug with that part number that will go to MB to ensure that the thread starts in the right place, and only use those that are spot-on, or they manufacture special plugs with the same part number just for MB? I'd think their engineering tolerances are at least as good as MB's, if not better, and every plug is spot-on.
- Joined
- Nov 29, 2002
- Messages
- 7,657
- Location
- London\Essex
- Car
- E63s s213 2019, E55 2004 Silver-SOLD, E63 w212 Weistec AMG-SOLD, E55 2004-SOLD, C36 1997-SOLD
Genuine MB plugs is the way to go even with a highly modded e63 they were the best plugs
- Joined
- Mar 11, 2013
- Messages
- 10,957
- Location
- South Bucks
- Car
- CLS63 SB, ML63, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
No argument there. NGK are genuine MB plugs; that's why MB buy them from NGK.
- Joined
- Nov 29, 2002
- Messages
- 7,657
- Location
- London\Essex
- Car
- E63s s213 2019, E55 2004 Silver-SOLD, E63 w212 Weistec AMG-SOLD, E55 2004-SOLD, C36 1997-SOLD
some items even from a certain manufacturer are slightly different and made specifically under livcense to a slightly different spec. no doubt the plugs are an off the shelf item, but you never know. also with a decent discount work out roughly the same from the dealers.
jimjamiejames
Active Member
- Joined
- Nov 5, 2007
- Messages
- 251
- Car
- S211 e350, daimler sovereign custom project
I need to do this job on my car. Does anyone have the relevant part numbers to hand. Mb and NGK.
- Joined
- Mar 11, 2013
- Messages
- 10,957
- Location
- South Bucks
- Car
- CLS63 SB, ML63, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
Part Finder - NGK Spark Plugs
Search by application to find the part you need from NGK or NTK
ngksparkplugs.com
When I had the little problem (which became a major problem...
) with my M157 E63 I could have told you, but that was a while ago and I can't recall the number now.- Joined
- Mar 11, 2013
- Messages
- 10,957
- Location
- South Bucks
- Car
- CLS63 SB, ML63, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
Stop Press: The Bosch part number is ZR6SII3320. (The engine problem was not related to the spark plugs). Those Bosch plugs were OE, I think, but I actually fitted MB plugs - bought from MB Newcastle, and only a little more expensive than the Bosch ones. In my posts about NGK plugs, for NGK read Bosch (I'm old; my memory's going; Doh!), but everything else is correct.
According to this video, around 8:10, the guy says the thread starts from the side on the aftermarket Bosch, whereas the factory issue Bosch spark plug, the thread starts from the front. The spark plug lives a bit closer in the combustion chamber in the M157, for peace of mind I would buy only from MB dealer and follow the indexing, for peace of mind.
Last edited:
- Joined
- Mar 11, 2013
- Messages
- 10,957
- Location
- South Bucks
- Car
- CLS63 SB, ML63, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
I'll watch that later; it's past my bedtime. If he's correct, then the Bosch aftermarket won't be indexed correctly on torque setting alone, and the Bosch part number will not be the same as you find on the OE plug.
FCP EURO, are non UK based company, equivalent to eurocarparts. I normally use their website to extract useful part numbers because they're pretty good with Mercedes and have a good knowledge base. They do seem to list off the shelf parts for the M157. They list part numbers NGK 97506 and Bosch 517013 for the M157. The spark plug in the M157 lives very very deep and close in the combustion chamber, will need a narrow extra long socket for this job and double check and compare where the thread starts between the original and replacement. If its not the same, return them back for refund. Changing spark plug on the M113/k and M156 its a doddle.
Last edited:
