Spark Plugs
MBWorld Fanatic!
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C63s Cabriolet, BMW M4, Civic
How can the Manual is wrong here....
I've changed spark plugs on all the Mercedes I owned in the past but never really compared the old to the new before install the new. I will now........after reading these thread.
https://mbworld.org/forums/c32-amg-c...ml#post5712089
https://mbworld.org/forums/c32-amg-c...ml#post5712089
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2004 CLK320
I emailed FCPEURO for the updated version of Bosch 7422 spark plugs for CLK320 and CL500.
They replied to say that 7742 has been replaced by 4418: Bosch Spark Plug - Bosch 4418 FGR8DQP (Platinum +4). I saw the picture and each plug has 4 tips on top.
In both Autohausaz and FCPEureo, 4418 is cheaper than 7742 for about $1.
I am leaning for the 7742 because this is what my local MB dealerships are using. Anyone has experience on this 4-tip platinum plugs?
They replied to say that 7742 has been replaced by 4418: Bosch Spark Plug - Bosch 4418 FGR8DQP (Platinum +4). I saw the picture and each plug has 4 tips on top.
In both Autohausaz and FCPEureo, 4418 is cheaper than 7742 for about $1.
I am leaning for the 7742 because this is what my local MB dealerships are using. Anyone has experience on this 4-tip platinum plugs?
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
That ring fire plug is an adaption of the old plug that Bosch made for Alfa Romeo in the sixties. The only benefit of, so called "ring fire" plugs is they are more likely to fire in the presence of oil. Italian engines used quite a lot of oil as they had no valve guide seals and plugs could oil up.
It's your car & you can fit whatever you wish. I would stick to the plugs that Benz fit in production. They cost more but they are designed to last 100K miles.
It's your car & you can fit whatever you wish. I would stick to the plugs that Benz fit in production. They cost more but they are designed to last 100K miles.
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2004 CLK320
By "fire ring" plugs, you are talking to about 4418, right?
I plan to stick to 7422. It is a bit tricky, stock plug is FR8DPP33 but it has been replaced by FR8DPP33+.
As for Alfa Romeo, I recall I had a friend who owned one of these 20-25 years ago. He had to add engine oil every time he fueled up at the gas station. He said the car had a high compression engine and it was normal to burn oil.
I plan to stick to 7422. It is a bit tricky, stock plug is FR8DPP33 but it has been replaced by FR8DPP33+.
As for Alfa Romeo, I recall I had a friend who owned one of these 20-25 years ago. He had to add engine oil every time he fueled up at the gas station. He said the car had a high compression engine and it was normal to burn oil.
Last edited by mis3; Jul 15, 2013 at 06:25 PM.
Super Moderator
Joined: Jun 2008
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Yes, the 4418 is ring fire.
If it was my car I would fit Bosch F 8 DPER if I could get them or Bosch FR-8-DPP-33+ (7422)
If it was my car I would fit Bosch F 8 DPER if I could get them or Bosch FR-8-DPP-33+ (7422)
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Joined: Jun 2008
Posts: 19,942
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
+1^ ~ the plug companies keep trying to reinvent the wheel. After lead errosion ceased to be an issue with unleaded fuels & really long life became feasible there is not much more they can do. It's materials vs cost now. The original Alfa plug was a work of art but not gappable. The latest effort is clumsy by comparison.
Alfa plug made by Bosch & Lodge.
Alfa plug made by Bosch & Lodge.
Last edited by Glyn M Ruck; Jul 16, 2013 at 07:55 AM.
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MBWorld Fanatic!
Joined: Jan 2004
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2004 CLK320
As I mentioned in my other post, I usually change my spark plugs every 100K KM (60K miles) for all my cars.
For my current w209, I changed my plugs on Mar, 2011, some 70K KM before (42 miles).
I know the frequency depends on many factors. Since I did not use my car for long trips for the past year, I am thinking to change my plugs earlier but is 42K miles too early?
For my current w209, I changed my plugs on Mar, 2011, some 70K KM before (42 miles).
I know the frequency depends on many factors. Since I did not use my car for long trips for the past year, I am thinking to change my plugs earlier but is 42K miles too early?
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2008 CLK550 Cab
Just did mine at 43,000 and glad I did. Very obvious pitting and/or little tiny blobs of melted metal deposits on the electrodes as they traded body fluids. Not terrible, but more than just dirty.
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2004 CLK320
Before I posted the quesiton, I did research on the service interval of spark plugs. It varies from 30K miles to 100k miles!
I read that it's better to change the plugs before the stated lifespan. Spark plugs deteriorate over time. On the other hand, I read that I should not touch the spark plugs and the wires unless it throws a code.
Does anyone know the OE of the spark plug cables?
I read that it's better to change the plugs before the stated lifespan. Spark plugs deteriorate over time. On the other hand, I read that I should not touch the spark plugs and the wires unless it throws a code.
Does anyone know the OE of the spark plug cables?
Last edited by mis3; Jul 24, 2013 at 10:56 AM.
MBWorld Fanatic!
Joined: Jun 2008
Posts: 1,227
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From: Atlanta Metro
2008 clk550 - Navigator - Frontier
Rodney, changed my plugs last week (Monday) and wanted to be able to say "my old plugs were better than your old plugs"........ but I can't. I started witth the passenger side and things were looking great. On the drivers side, my bragging hopes were dashed.... 
Any thoughts (from anyone) based on the attached 4 pics?
1 pass side plugs on left (random order) - drv side plugs (rear to front)
2 close up of pass side plugs
3 close up of drv side plugs
4 close up of drv side plugs
The dark stuff is sorta "carmelized". Had not noticed any issues in driving. But I have noticed more "punch" when I accelerated "briskly" from any speed since changing the plugs.
Just wondering if I should hold my "self insurance" money for another year before blowing it.
I plan to pull the drv side rear and front plugs after 2K miles and visually checking them.
thx
Any thoughts (from anyone) based on the attached 4 pics?
1 pass side plugs on left (random order) - drv side plugs (rear to front)
2 close up of pass side plugs
3 close up of drv side plugs
4 close up of drv side plugs
The dark stuff is sorta "carmelized". Had not noticed any issues in driving. But I have noticed more "punch" when I accelerated "briskly" from any speed since changing the plugs.
Just wondering if I should hold my "self insurance" money for another year before blowing it.
I plan to pull the drv side rear and front plugs after 2K miles and visually checking them.
thx
MBWorld Fanatic!
Joined: Jun 2008
Posts: 1,227
Likes: 61
From: Atlanta Metro
2008 clk550 - Navigator - Frontier
Rodney, changed my plugs last week (Monday) and wanted to be able to say "my old plugs were better than your old plugs"........ but I can't. I started witth the passenger side and things were looking great. On the drivers side, my bragging hopes were dashed....
Any thoughts (from anyone) based on the attached 4 pics?
1 pass side plugs on left (random order) - drv side plugs (rear to front)
2 close up of pass side plugs
3 close up of drv side plugs
4 close up of drv side plugs
The dark stuff is sorta "carmelized". Had not noticed any issues in driving. But I have noticed more "punch" when I accelerated "briskly" from any speed since changing the plugs.
Just wondering if I should hold my "self insurance" money for another year before blowing it.
I plan to pull the drv side rear and front plugs after 2K miles and visually checking them.
thx
Any thoughts (from anyone) based on the attached 4 pics?
1 pass side plugs on left (random order) - drv side plugs (rear to front)
2 close up of pass side plugs
3 close up of drv side plugs
4 close up of drv side plugs
The dark stuff is sorta "carmelized". Had not noticed any issues in driving. But I have noticed more "punch" when I accelerated "briskly" from any speed since changing the plugs.
Just wondering if I should hold my "self insurance" money for another year before blowing it.
I plan to pull the drv side rear and front plugs after 2K miles and visually checking them.
thx
Super Moderator
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
All those plugs look absolutely fine. It's only the tips that matter.
The goo on the threads is due to burnt on lubricant of some sort when they were fitted & possibly they were not torqued correctly against the crush washer.
There is a lot of controversy about applying anti seize or whatever compounds to plug threads in aluminium heads.
Many plug manuafacturers believe that the zinc plating on the threads is sufficient anti seize & that applying any form of lubricant causes over torquing of the plugs affecting heat transfer.
Anyway ~ your plugs are fine. Nothing to worry about.
The goo on the threads is due to burnt on lubricant of some sort when they were fitted & possibly they were not torqued correctly against the crush washer.
There is a lot of controversy about applying anti seize or whatever compounds to plug threads in aluminium heads.
Many plug manuafacturers believe that the zinc plating on the threads is sufficient anti seize & that applying any form of lubricant causes over torquing of the plugs affecting heat transfer.
Anyway ~ your plugs are fine. Nothing to worry about.
