Non Resistor Spark Plug List

[anderzen]

Hello All,

I know...I know, BOSCH F8DC4!
BUT! I want to know and I'd imagine others do as well... What are some other Non Resistor Plugs available? Maybe even some that could be more easily found at Local Auto Parts stores in a pinch... and just in general, would be nice to have a direct list of KNOWN non-resistor plugs as they are pretty hard to find now a days...
From Cross referencing, I have found quite a few 'Race' plugs that are non resistor but their heat ranges are either not on par or unable to be cross compared with say a Bosch 8 and NGK 5 heat range.
I'll wait till we discuss things a bit but plan to add and adjust to a list so that eventually, surfers can just drop in and see a list of usable options rather than scour threads or the web.

Spark Plug Dimensions:
Thread: 14x1.25
Reach: 19mm (3/4)
Hex: 16mm (5/8)
Resistor: No

The List (will grow here):

• Bosch F8DC4
• NGK BK5E
• NGK BK5E-11
• Champion C10YCC
• Beru 14F-8DUO (Dealer # 003-159-68-03)
• Brisk D17YC

Mods.. you can move this elsewhere or wherever you see fit.

Thx!
ANDERZÉN

 

[500AMM]

The radiator cross member sticker is listing Beru 14F-8DUO and Champion C10YCC as well. I haven't checked the availability on these plugs. I ran with Denso on my ex. Limited and they worked fine, can't recall their specific number right now.

 

[gsxr]

Arnt is correct. The dealer plugs are 003-159-68-03, which are MB-branded Beru 14F-8DUO. Fabriqué in France. Currently $5 each MSRP in USA.

AFAIK all the Bosch F8DC4 currently available in USA are made in Russia. Dunno how the war is affecting production or availability. Remember to gap to 1.0-1.1mm for normal use (normally aspirated, no NOS).

 

[anderzen]

Thanks Guys! Added to the list!

If you remember that Denso # @500AMM or anyone else let me know!

Just ordered the Bosch's 10 pack for $33

 

[Jlaa]

There was a dude on ebay selling these - 003-159-67-03-26 for some crazy ridiculously good price ... like maybe it was $20 for a box of 10? These are MB Branded Bosch made in Germany. I bought like a lifetime's supply of these. These might still be available on ebay if you look hard enough.

 

[anderzen]

Added another to the list.. a pretty cool one! Brisk D17YC which is a Copper Racing Non Resistor Plug, purchased a set on Summit for $40 shipped, the heat range and specs are the same as my M113 in the C55 for the M119 which I didn't realize at first.

 

[500AMM]

I have a good supply of the same plugs as @Jlaa, bought them from member @clarkz back in 2015 along with a set of custom length Beru silicon/copper plug wires. P/N# 003 159 16 03 in the image below is the OE with Bosch designation F-7DCO for the 6.0 AMG

 

[anderzen]

So would either 7 or 8 heat range from Bosch be ok for 4.2, 5.0 and 6.0 etc?

My M113’s can run either 7 or 8

 

[500AMM]

#7 is a colder heat rating, but I guess you won't notice any difference on normal driving by using #7 or #8. But it's important not to go the other way with increased heat rating. Here is a nice site explaining Bosch spark plug characteristics:
https://www.boschsparkplugs.net/what-is-a-spark-plugs-heat-range-2

Just for posterity, enclosed some images snagged from someone (Dave maybe..?) here on the board comparing country of origin.

 

[anderzen]

Interesting... I ordered 24 (8 for E420 and 16 for C55) of the Brisk 17 Heat range which is a Bosch 8 or NGK 5 thinking that is what I had been running in my C55. However it was tuned on NGK 6 heat range actually, so now I am thinking I should've got Brisk D15YC to match....

 

[nikitino25]

Just ordered these plugs for my '93 400E Mercedes Bosch Spark Plug - Bosch F8DC4

which I hope is the correct plug. Also going to try Mercedessource Kent's method of removal and install with the rubber hose:

What size spark plug socket do I need though? I have a magnetic 14mm BMW spark plug socket, will that work?

 

[anderzen]

Just did them, 16mm socket, and yes I used 3/8 silicone hose just like that and made it a breeze!

 

[anderzen]

To also update… I pulled F8DC4+ out of the car, they were in good shape but gapped to .30 instead of .40

Needless to say, non resistor F8DC4 are in now. Admittedly don’t feel much of a difference just yet, but need to drive it some more.

 

[gsxr]

To also update… I pulled F8DC4+ out of the car, they were in good shape but gapped to .30 instead of .40

Needless to say, non resistor F8DC4 are in now. Admittedly don’t feel much of a difference just yet, but need to drive it some more.

Don't expect a power difference... if anything, it may be a bit smoother at idle, and/or not hiccup at hot idle.

 

[gsxr]

I wonder if Uncle Kent doesn't wrench on M119's often. I see the gooey brown stuff on the plug threads all the time, on ALL of my M119 engines, over nearly 20 years. That video was shot nearly 10 years ago, btw.

Also, while the OE Hazet spark plug socket isn't cheap, it's well worth the expense if within your budget. It grips the plug tightly to allow removal and installation, no hose required. Not sure if it's available aftermarket for less, most dealers want $60-$65 for the darn thing:

Spark Plug Wrench 119-589-02-09-00 | MB Online Parts

119-589-02-09-00 - Spark Plug Wrench

www.mbonlineparts.com

 

[nikitino25]

So the correct gap is .40? I thought I read it was supposed to be 1-1.2 millimeter.......this is for a 400E

 

[nikitino25]

Just ordered this socket from ebay, we'll see how it works:

1x Universal Car 16mm3/8"Magnetic Thin Wall Joint Spark Plug Socket Removal Tool | eBay

Description: 16mm 3/8" Drive Thin Wall Swivel Magnetic Spark Plug Wobble Socket Constructed Of Heat-Treated Chrome Vanadium Steel Chrome Plating, With Wobble Function. 360-Degree Swivel Design For Maximum Flexibility, Skid Resistance Shaft And Socket For Enhanced Grip. Interior Magnet Retains...

www.ebay.com

 

[gsxr]

So the correct gap is .40? I thought I read it was supposed to be 1-1.2 millimeter.......this is for a 400E

Factory spec is 0.8mm (0.031").

Recommended gap for new plugs is 1.0-1.1mm (0.039-0.043").

 

[gerryvz]

To also update… I pulled F8DC4+ out of the car, they were in good shape but gapped to .30 instead of .40

Needless to say, non resistor F8DC4 are in now. Admittedly don’t feel much of a difference just yet, but need to drive it some more.

Dont expect a power difference... if anything, it may be a bit smoother at idle, and/or not hiccup at hot idle.

You won't feel any difference in power or running characteristics. I ran resistor F8's in my E500 for about 12 years, not knowing it, because a mechanic (the last time I ever had someone else work on my car in 2009) installed the wrong plugs. Never noticed any issues.

Needless to say, when I installed new plugs in 2020, the correct factory German Bosch F8DC4s went into the cylinder heads.

 

[gerryvz]

I wonder if Uncle Kent doesnt wrench on M119s often. I see the gooey brown stuff on the plug threads all the time, on ALL of my M119 engines, over nearly 20 years. That video was shot nearly 10 years ago, btw.

Also, while the OE Hazet spark plug socket isnt cheap, its well worth the expense if within your budget. It grips the plug tightly to allow removal and installation, no hose required. Not sure if its available aftermarket for less, most dealers want $60-$65 for the darn thing:

Spark Plug Wrench 119-589-02-09-00 | MB Online Parts

119-589-02-09-00 - Spark Plug Wrench

www.mbonlineparts.com

View attachment 161532

An EXCELLENT alternative to the factory spark plug wrench, complete with magnetic tip to grip the plug, and swivel shaft, is available from Amazon for a good price. It's made by GearWrench. $14 at Amazon.

They also make a separate version for the larger diameter M117 spark plugs, if needed.

Amazon.com

 

[Ascension]

I wonder if Uncle Kent doesnt wrench on M119s often. I see the gooey brown stuff on the plug threads all the time, on ALL of my M119 engines, over nearly 20 years. That video was shot nearly 10 years ago, btw.

Also, while the OE Hazet spark plug socket isnt cheap, its well worth the expense if within your budget. It grips the plug tightly to allow removal and installation, no hose required. Not sure if its available aftermarket for less, most dealers want $60-$65 for the darn thing:

Spark Plug Wrench 119-589-02-09-00 | MB Online Parts

119-589-02-09-00 - Spark Plug Wrench

www.mbonlineparts.com

View attachment 161532

Never seen one of those. Have several plug sockets that grip well enough on the plug, my issue is they grip so well that the extension come off the socket before the socket releases from the plug.

 

[Jlaa]

An EXCELLENT alternative to the factory spark plug wrench, complete with magnetic tip to grip the plug, and swivel shaft, is available from Amazon for a good price. Its made by GearWrench. $14 at Amazon.

They also make a separate version for the larger diameter M117 spark plugs, if needed.

Amazon.com

Sweet! Made in Taiwan for the win! BTW this is 12.99 on Amzn if you select “Vera Tools” as the vendor.

 

[500AMM]

While into spark plug tools, here is the two Hazet wrenches (none OE) for 16mm hex with the spring pickup inside. I think the longest wrench is too long to access the two inner plugs on both banks; #3 #4 #7 #8

Hazet #4766, 97mm

Hazet #4766-1, 270mm


Be aware and don't mix-up with Hazet 4766-2 and 4766-3 which is for 14mm hex. (Moderator edit: the M156 engine uses these smaller sockets.)

 

[albdentist]

HAZET 4766 - Spark plug wrench | Mister Worker™

Buy online at the best price: HAZET 4766 Spark plug wrench. Discover Lubrication, filtration and spark plugs by HAZET for sale on Mister Worker™. Fast delivery and Custom Quotes.

www.misterworker.com

HAZET 4766-1 - Spark plug wrench | Mister Worker™

Buy online at the best price: HAZET 4766-1 Spark plug wrench. Discover Lubrication, filtration and spark plugs by HAZET for sale on Mister Worker™. Fast delivery and Custom Quotes.

www.misterworker.com

i have had good luck with this site...

 

[anderzen]

Definitely good dedicated tools out there if that is your thing. Was an absolute breeze with just 16mm deep socket, small/medium 3/8th extensions and the 3/8th hose of choice, all of which I'm sure everyone has laying around. To each their own, just sayin! Took me ten minutes start to finish

 

[Ascension]

An EXCELLENT alternative to the factory spark plug wrench, complete with magnetic tip to grip the plug, and swivel shaft, is available from Amazon for a good price. Its made by GearWrench. $14 at Amazon.

They also make a separate version for the larger diameter M117 spark plugs, if needed.

Amazon.com

Thanks for posting that Gerry I have one incoming as of last night. Have fought with this on several cars I own with plugs deep in wells thanks for a great solution that won't kill my wallet!

 

[Ascension]

Definitely good dedicated tools out there if that is your thing. Was an absolute breeze with just 16mm deep socket, small/medium 3/8th extensions and the 3/8th hose of choice, all of which Im sure everyone has laying around. To each their own, just sayin! Took me ten minutes start to finish

Also have several good real plug sockets that hold the plug well. My issue is they all hold the plugs so well you cant get the socket off the plug after you install them. That's because the socket comes off the extension before the socket releases the plug. It's maddening and I have several with plugs in deep wells that I have the same problem with. It was a no brainier to grab that magnetic Gear Wrench with the built in swivel and solve that problem .

 

[500AMM]

Also have several good real plug sockets that hold the plug well. My issue is they all hold the plugs so well you cant get the socket off the plug after you install them. Thats because the socket comes off the extension before the socket releases the plug. Its maddening and I have several with plugs in deep wells that I have the same problem with. It was a no brainier to grab that magnetic Gear Wrench with the built in swivel and solve that problem .

I concur, but it helps to moisten that rubber grommet inside a little bit with water/oil/grease. But I'm due to find something better now.

 

[anderzen]

my process of replacement: here

Once my Brisk plugs show up I'll use them on the refreshed 5.0 once we swap it in.

 

[luckymike]

I concur, but it helps to moisten that rubber grommet inside a little bit with water/oil/grease. But Im due to find something better now.

I use locking extensions.

 

[nikitino25]

So I ordered oe MB plugs which I thought would be the F8DC4 plugs but they sent me these made in France, 14F-8DU4….will these work fine for my 400E? Ordered them through a dealer and I guess they just sent me what they had

 

[gsxr]

So I ordered oe MB plugs which I thought would be the F8DC4 plugs but they sent me these made in France, 14F-8DU4….will these work fine for my 400E? Ordered them through a dealer and I guess they just sent me what they had

Those are fine. They are Beru equivalents to the Bosch F8DC4.

The OE F8DC4 went NLA several years ago, only aftermarket F8DC4 are available now, as described earlier in this thread.

 

[nikitino25]

Awesome, thanks for the quick response.......I'm assuming these are non resistor plugs? The tips look different than all the pics of the other plugs (dark bronze or black almost) instead of gold or silver

 

[nikitino25]

I see now that the Beru

Arnt is correct. The dealer plugs are 003-159-68-03, which are MB-branded Beru 14F-8DUO. Fabriqué in France. Currently $5 each MSRP in USA.

AFAIK all the Bosch F8DC4 currently available in USA are made in Russia. Dunno how the war is affecting production or availability. Remember to

I see above where these plugs are compatible I just wanted the actual Bosch plugs

 

[gsxr]

I see above where these plugs are compatible I just wanted the actual Bosch plugs

Bosch F8DC4 are only available aftermarket now. Not from any dealership.

The Berus are proper non-resistor plugs. There's no advantage to Bosch over Beru that I'm aware of.

 

[gerryvz]

There is ZERO stigma nor quality difference in the Bosch F8DC4s available on the aftermarket (made in Russia, or in the past Brazil), and the Germany-made Bosch F8DC4s that MB used to sell. Other than having the MB star on them and a different COO.

The Russian-made F8s work just fine and are excellent plugs. I would not hesitate to put them on my car, and actually have a box of them as spares and alternatives to the MB Bosch Germany F8DC4s that I have a couple of boxes of, as well.

 

[rayhennig]

Factory spec is 0.8mm (0.031").

Recommended gap for new plugs is 1.0-1.1mm (0.039-0.043").

Why would factory and recommended be different.

I just bunged in my MB Berus without checking gap. All seems very well.

R

 

[gsxr]

TLDR: The larger gap may help reduce the hot idle hiccup which is common on these engines.

Lots of discussion on this years ago on the forum, search for details.

 

[gsxr]

In related news, many/most of the non-resistor plugs have gone NLA recently. I'm not sure exactly when this occurred, could have been a year or two ago. Years ago I had purchased a couple of sets of NGK BCP6ES plugs as a low-cost alternative to the factory Bosch F7DCO used on the M119 6L engines, the NGK's were under $2/ea, while the dealer F7DCO were >$5/ea.

Now, all the NGK, Champion, and other non-resistor equivalents are discontinued. They have been replaced with resistor versions instead. The F7DCO are still available from Mercedes, for now. This is a non-issue for 4.2L and 5.0L applications, without forced induction or NOS. But if you want a colder plug for forced induction or NOS, options have become limited.

 

[rayhennig]

The larger gap may help reduce the hot idle hiccup which is common on these engines.

Ah! Mine's a 6 cyl M104.980. Maybe be not so critical?

R

 

[gsxr]

Ah! Mine's a 6 cyl M104.980. Maybe be not so critical?

I think the same still applies on the M104 (and M116/M117), but if you have a smooth idle at full operating temp - don't worry about it!

 

[jmanbball]

In related news, many/most of the non-resistor plugs have gone NLA recently. I'm not sure exactly when this occurred, could have been a year or two ago. Years ago I had purchased a couple of sets of NGK BCP6ES plugs as a low-cost alternative to the factory Bosch F7DCO used on the M119 6L engines, the NGK's were under $2/ea, while the dealer F7DCO were >$5/ea.

Now, all the NGK, Champion, and other non-resistor equivalents are discontinued. They have been replaced with resistor versions instead. The F7DCO are still available from Mercedes, for now. This is a non-issue for 4.2L and 5.0L applications, without forced induction or NOS. But if you want a colder plug for forced induction or NOS, options have become limited.

I was recently trying to buy some BCP6ES for my M104, but they were really hard to find. That must be why! Ended up going with Russian F8DC4's. One green and 5 blue

 

[gsxr]

I was recently trying to buy some BCP6ES for my M104, but they were really hard to find. That must be why! Ended up going with Russian F8DC4's. One green and 5 blue

The F7DCO non-resistor plug is equivalent to the BCP6ES, available new from Mercedes, and made in Germany as a bonus.

MB p/n 003-159-16-03, $6/ea MSRP, $4.50 from discount dealers like Naperville (link below, free ship over $100 with code 500EPROMO).

Spark Plug 003-159-16-03 | MB OEM Parts

003-159-16-03 - Spark Plug

www.mboemparts.com

 

[yao500e]

Hello All,

I know...I know, BOSCH F8DC4!
BUT! I want to know and I'd imagine others do as well... What are some other Non Resistor Plugs available? Maybe even some that could be more easily found at Local Auto Parts stores in a pinch... and just in general, would be nice to have a direct list of KNOWN non-resistor plugs as they are pretty hard to find now a days...
From Cross referencing, I have found quite a few 'Race' plugs that are non resistor but their heat ranges are either not on par or unable to be cross compared with say a Bosch 8 and NGK 5 heat range.
I'll wait till we discuss things a bit but plan to add and adjust to a list so that eventually, surfers can just drop in and see a list of usable options rather than scour threads or the web.

Spark Plug Dimensions:
Thread: 14x1.25
Reach: 19mm (3/4)
Hex: 16mm (5/8)
Resistor: No

The List (will grow here):

• Bosch F8DC4
• NGK BK5E
• NGK BK5E-11
• Champion C10YCC
• Beru 14F-8DUO (Dealer # 003-159-68-03)
• Brisk D17YC

Mods.. you can move this elsewhere or wherever you see fit.

Thx!
ANDERZÉN

Anderzen, super helpful information. Also, i know, i know! Bosch F8DC4, i know! but I got a buddy who is running non-resistor Denso Iridium on his C36 with excellent results. Im so tempted to try. lol. He is running sub 14's 1/4 mile in stock 1995 C36.

 

[gsxr]

Anderzen, super helpful information. Also, i know, i know! Bosch F8DC4, i know! but I got a buddy who is running non-resistor Denso Iridium on his C36 with excellent results. Im so tempted to try. lol. He is running sub 14's 1/4 mile in stock 1995 C36.

Models with distributor ignitions should stick with non-resistor plugs.

Models with coil-on-plug ignition could experiment with resistor and/or exotic-element plugs, although in general the main advantage is longer lifespan of the plug, NOT increased power.

 

[yao500e]

Models with distributor ignitions should stick with non-resistor plugs.

Models with coil-on-plug ignition could experiment with resistor and/or exotic-element plugs, although in general the main advantage is longer lifespan of the plug, NOT increased power.

appreciate this. so since both 500e m119 and C36 m104 are coil-on-plug, this explains how some owners decided to try Denso Iridium and reporting good results.

As long as Denso Iridium doesnt damage anything, I guess it would be ok to use. thanks again.

 

[TerryA]

appreciate this. so since both 500e m119 and C36 m104 are coil-on-plug, this explains how some owners decided to try Denso Iridium and reporting good results.

As long as Denso Iridium doesnt damage anything, I guess it would be ok to use. thanks again.

@yao500e,
As far as I know only the E500 has coil on plug. I have a 1993 and no coil on plug.

 

[ArauzMotoring]

@yao500e,
As far as I know only the E500 has coil on plug. I have a 1993 and no coil on plug.

Whattt

I want my 500E to have coil on plugs

 

[gsxr]

appreciate this. so since both 500e m119 and C36 m104 are coil-on-plug...

C36 and all M104 HFM engines are coil-on-plug.

All W124 E500E have M119.97x with dual distributors. All M119's through 1995 USA model year have distributors.

Only M119.978x have coil-on-plug ignition with ME 1.0 injection. This was only from 1996-1999 USA model years (and in 1999, the only chassis still using the M119 was the 140).

 

[yao500e]

C36 and all M104 HFM engines are coil-on-plug.

All W124 E500E have M119.97x with dual distributors. All M119's through 1995 USA model year have distributors.

Only M119.978x have coil-on-plug ignition with ME 1.0 injection. This was only from 1996-1999 USA model years (and in 1999, the only chassis still using the M119 was the 140).

Thanks again @gsxr
I been researching a bit and it seems iridium works well and ok with coil-on ignitions