spark plug BOSCH F8DC4 vs F8DC0 - Page 9 - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
post #81 of 171 (permalink) Old 01-14-2018, 05:08 AM
BenzWorld Elite
 
samosali's Avatar
 
Date registered: Nov 2007
Vehicle: W140 Mercedes 500 SE, 1992, European, 410.000 km
Location: Slovenia (Europe)
Posts: 3,514
Mentioned: 0 Post(s)
Quoted: 269 Post(s)
Quote:
I alway read our combustion chamber's were not clean enough to run fine wire plugs.We need the larger diameter electrodes,I like my champion spark plugs.As bosch ones foul out to easy from carbon.
i must admit this this sounds like you read something which is called a "myth". as an engineer i do not see any chance (reason) that combustion chamber in our cars is more dirty as any other combustion chamber in any other car in the world.

All I wish for Christmas is a smooth idle.
samosali is offline  
Sponsored Links
Advertisement
 
post #82 of 171 (permalink) Old 01-14-2018, 05:36 AM
BenzWorld Member
 
Nate D. Rector's Avatar
 
Date registered: Aug 2016
Vehicle: 99 s320 member since 2009 fastest time 14.6 1/4 mile nitrous.
Location: elizabethton tn
Posts: 386
Mentioned: 0 Post(s)
Quoted: 108 Post(s)
tolerances not as tight,allowing crap to get in.
Nate D. Rector is offline  
post #83 of 171 (permalink) Old 01-14-2018, 06:29 AM
BenzWorld Junior Member
 
Arm Strong's Avatar
 
Date registered: Nov 2016
Vehicle: 1991 r129.066 500SL, 1968 W108.014 280SE
Location: Thailand
Posts: 38
Mentioned: 0 Post(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by Nate D. Rector View Post
...As bosch ones foul out to easy from carbon...

Could you explain your plug heat range please?
Arm Strong is offline  
Sponsored Links
Advertisement
 
post #84 of 171 (permalink) Old 01-14-2018, 06:57 AM
BenzWorld Elite
 
samosali's Avatar
 
Date registered: Nov 2007
Vehicle: W140 Mercedes 500 SE, 1992, European, 410.000 km
Location: Slovenia (Europe)
Posts: 3,514
Mentioned: 0 Post(s)
Quoted: 269 Post(s)
Quote:
tolerances not as tight,allowing crap to get in.
i do not get it. any car air filter is approximately the same and the second way to get crap in is fuel injector which has a fuel filter before it.

All I wish for Christmas is a smooth idle.
samosali is offline  
post #85 of 171 (permalink) Old 01-14-2018, 12:07 PM
BenzWorld Elite
 
gsxr's Avatar
 
Date registered: Aug 2002
Vehicle: Buncha W124's
Location: Boise, ID
Posts: 2,013
Mentioned: 3 Post(s)
Quoted: 118 Post(s)
Quote:
Originally Posted by hamada128 View Post
Installed the IR NGK today. Idle is still smooth in both conditions, I feel the engine is more responsive but that may be my driver side seatometer only.
Here are some pictures of the non-resistors F8DC0 plugs I removed from the engine after 2 years/ almost 20k miles, what do you think of the condition?
Left to right order is = No 6 - 1 Cyl.
I'm not sure why multiple people think those plugs look normal. To my eyes, they appear very dark, indicating an abnormally rich condition. They appear to be what NGK and Bosch refer to as "dry fouled" or "carbon fouled".

Photos attached below show what I typically see on the dozen-plus M119 engines I've owned.

Here are links to pictures of how to read plugs, from NGK and Bosch:

https://www.ngksparkplugs.com/about-...d-a-spark-plug

https://www.ipdusa.com/blogs/151/bosch-spark-plug-faq
Attached Thumbnails
Click image for larger version

Name:	used_plugs1.jpg
Views:	237
Size:	63.4 KB
ID:	2352826   Click image for larger version

Name:	used_plugs2.jpg
Views:	82
Size:	64.8 KB
ID:	2352834  
gsxr is offline  
post #86 of 171 (permalink) Old 01-14-2018, 12:30 PM
BenzWorld Elite
 
hamada128's Avatar
 
Date registered: Jan 2007
Vehicle: 93 190E 2.3, 94 E320 (sold), 01 E320, 99 S320, 18 Durango
Location: NJ, USA
Posts: 4,938
Mentioned: 4 Post(s)
Quoted: 478 Post(s)
Quote:
Originally Posted by gsxr View Post
I'm not sure why multiple people think those plugs look normal. To my eyes, they appear very dark, indicating an abnormally rich condition. They appear to be what NGK and Bosch refer to as "dry fouled" or "carbon fouled".

Photos attached below show what I typically see on the dozen-plus M119 engines I've owned.

Here are links to pictures of how to read plugs, from NGK and Bosch:

https://www.ngksparkplugs.com/about-...d-a-spark-plug

https://www.ipdusa.com/blogs/151/bosch-spark-plug-faq
What could cause that?
Within the past 6-12 months I replaced air filter/mass air sensor/O2 sensors/plug wires/ignition coils/oil change.

Last edited by hamada128; 01-15-2018 at 04:52 AM. Reason: Added O2 sensors
hamada128 is offline  
post #87 of 171 (permalink) Old 01-14-2018, 01:58 PM
BenzWorld Elite
 
samosali's Avatar
 
Date registered: Nov 2007
Vehicle: W140 Mercedes 500 SE, 1992, European, 410.000 km
Location: Slovenia (Europe)
Posts: 3,514
Mentioned: 0 Post(s)
Quoted: 269 Post(s)
Quote:
What could cause that?
Within the past 6-12 months I replaced air filter/mass air sensor/plug wires/ignition coils/oil change.
i still think your spark plugs are near to perfect. I guess your car is not new. beside that your pictures are not made in optimal conditions. To me they do not appear very dark but lightly dark if at all.

All I wish for Christmas is a smooth idle.
samosali is offline  
post #88 of 171 (permalink) Old 01-14-2018, 04:18 PM
BenzWorld Elite
 
hamada128's Avatar
 
Date registered: Jan 2007
Vehicle: 93 190E 2.3, 94 E320 (sold), 01 E320, 99 S320, 18 Durango
Location: NJ, USA
Posts: 4,938
Mentioned: 4 Post(s)
Quoted: 478 Post(s)
Quote:
Originally Posted by samosali View Post
i still think your spark plugs are near to perfect. I guess your car is not new. beside that your pictures are not made in optimal conditions. To me they do not appear very dark but lightly dark if at all.
I will take better pictures tomorrow.
hamada128 is offline  
post #89 of 171 (permalink) Old 01-14-2018, 09:40 PM
BenzWorld Veteran
 
Date registered: Dec 2015
Vehicle: W140 1994 S500 USDM base model, before facelift
Location: Ohio
Posts: 618
Mentioned: 1 Post(s)
Quoted: 74 Post(s)
1. Plugs on the picture look ok for 30k conventional plugs, excatly the condition of the plug to be replaced.
2. Iridium plugs more tolerant to the residue and better self clean then conventional (allowing for longer intervals)
3. M119 has tight clearences and is not that different from modern cars, even more, it has much less carbon build up then modern DI cars, especially german. They are falling behind these days with carbon build up big time.
Modern engines have different sump ventilation system and different programming, they bypass (blow by) more oil, which is being burned creating more deposits. It is done to reduce friction, reduce pollution and improve mpg. This is why oil standards grow like grass on the rainy day... etc. I don't want to write more about it, enough is written on-line. But new engines produce more crap then old ones in the form of the deposits. Exception is only lexus/toyota with their patented dual injection (di and usual the same time).
4. Based on the picures, i'd suggest to replace o2 sensor if it is old, if you have replaced it, may be clean intake and throttle body (amsoil power foam). Exception, if you have more then one sensor (cars after 1996?)... may be just test them, kind of expensive to replace.
5. Based of what i've seen on my car and many other non-mb cars, your plugs are somewhat more black then they need to be, but not much. Mine came out the same (do not know how nany miles they were in). I blamed o2 sensor and throttle body, this summer i can say for sure.
My idle issues confirm this guess, mixture and plugs are interconnected: worse spark changes burning and mixture, wrong mixture darkens plugs, more unburned fuel deposits on the o2 sensor and so on... if you tell us which components have not been replaced for a while, we could guess better
samosali likes this.
Alter is offline  
post #90 of 171 (permalink) Old 01-15-2018, 04:51 AM
BenzWorld Elite
 
hamada128's Avatar
 
Date registered: Jan 2007
Vehicle: 93 190E 2.3, 94 E320 (sold), 01 E320, 99 S320, 18 Durango
Location: NJ, USA
Posts: 4,938
Mentioned: 4 Post(s)
Quoted: 478 Post(s)
I forgot to mention that both O2 sensors were replaced as well.
The only thing I can think of is those 20k miles in 2.5 years were mainly short trips with 30%hwy - 70% city.
Arm Strong likes this.
hamada128 is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Sedan Forums > W140 S-Class

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Topic Author Forum Replies Last Post
Bosch changed spark plug heat range imon_2nd W124 E,CE,D,TD Class 2 01-06-2007 10:33 PM
Bosch spark plug question benzwag W126 S,SE,SEC,SEL,SD,SDL Class 31 12-14-2006 10:20 AM
replacement spark plug wires sets - Bosch or Karlyn? andrew TD W140 S-Class 2 01-26-2006 01:51 PM
Bosch Spark Plug wires daveward General Mercedes-Benz 3 01-03-2006 12:10 AM
I am looking Bosch Platinum +4 spark plug for my 98 slk230, anyone can show the porduct # ondiet R170 SLK-Class 3 04-19-2002 11:34 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome