Mercedes spark plug

[Oldcar]

M119 PLUG
Costs $ 5.50 from the dealership
Made in France F8DU4
Solid tip not screw on

 

[emerydc8]

I just ordered the 003 159 68 03 from www.mbpartsource.com and they were $4.06.

 

[gerryvz]

M119 PLUG
Costs $ 5.50 from the dealership
Made in France F8DU4
Solid tip not screw on

Arte you selling these plugs, or is this just an FYI to members here?

 

[500AMM]

Is F8DU4 a replacement for the original F8DC4 (#003 159 67 03 26)?

 

[gsxr]

Yes, but the full designation is actually 14F-8DU4. These are Beru plugs made in France. They are equivalent to Bosch F8DC4.

Photos below from W124performance.com:

 

[500AMM]

Yes, but the full designation is actually 14F-8DU4. These are Beru plugs made in France. They are equivalent to Bosch F8DC4.

Photos below from W124performance.com:

Ahh, that explains it all, I didn't notice the first numbers!

 

[Oldcar]

Arte you selling these plugs, or is this just an FYI to members here?

I stoped at dealer and picked up in person .....saw better prices online..but not after shipping
..was driving past dealer yesterday anyhow ...the plugs seem better than the old f8dc4

Will give performance update after I install and drive comparing the new
14f-8du4 to f8dc4 with some miles on them.

 

[The Emperor]

 

[Oldcar]

Yes, but the full designation is actually 14F-8DU4. These are Beru plugs made in France. They are equivalent to Bosch F8DC4.

Photos below from W124performance.com:



View attachment 217612 View attachment 217613

WHO IS EMPEROR GUY?

 

[gsxr]

WHO IS EMPEROR GUY?

A dude you don't want to mess with!

 

[nocfn]

just some cracker that shows up a time or two to break ballz

 

[The Emperor]

WHO IS EMPEROR GUY?

 

[The Emperor]

A dude you don't want to mess with!

 

[Oldcar]

View attachment 217744

Maybe gsxr's cousin ?...lol

 

[Oldcar]

Arte you selling these plugs, or is this just an FYI to members here?

Fyi

Do you favor 14f-8du4 over the original bosch?
.

 

[gerryvz]

There is really no need for an LH-based M119, especially in stock form, to need anything other than an F8DC4 -- MB branded, Beru, Bosch, or the NGK equivalent.

Plugs for these cars is like motor oil. Just go with a branded product of good quality, and appropriate weight. So many people over-think plugs, and motor oil.

 

[500AMM]

I ran Denso spark plugs on my exLimited and they held up flawlessly.
AFAIK, no motorsport race is won on the spark plugs.

 

[Oldcar]

There is really no need for an LH-based M119, especially in stock form, to need anything other than an F8DC4 -- MB branded, Beru, Bosch, or the NGK equivalent.

Plugs for these cars is like motor oil. Just go with a branded product of good quality, and appropriate weight. So many people over-think plugs, and motor

Ok so if I understand correctly, the mercedes beru currently available is not better than the old bosch... (russisn bosch NA due to poor quality).

Are you referring to ngk bk5e as ok as well?

 

[gerryvz]

I’ve never seen a problem with a Russian or Brazilian made Bosch F8DC4 plug. In fact I have a new box of them out on my shelf right now. I would not hesitate to use them.

The French-made Beru and German-made Bosch F8DC4 plugs that are (or have been in the past) the MB-branded options, are equivalent in terms of function and quality. I would not hesitate to use them. I have a new box of Bosch MB F8DC4 plugs out on my shelf, as well.

MB has parts built to a specification that it defines and provides. Any MB-branded part that meets that specification, is good to go in MB’s book. Beru, Bosch….doesn’t matter. Meets specs — is good to sell.

I would not hesitate to use any NGK or Denso plug in an MB application, as long as it was the correct spec, heat range and non-resistor design. I don’t know the part numbers for these brands, but based on using them in other non-MB applications, I would not hesitate to use them in an M119, if that was all that was available. However I would always prefer Bosch or Beru if I had the choice.

I would NOT use Champion, Motorcraft, AC Delco, Mopar, or other parts of this type in an M119. There are better spark plug alternatives available, as outlined above.

 

[The Emperor]

Maybe gsxr's cousin ?...lol

 

[Oldcar]

View attachment 217844

Any final word on Russian f8dc4 plugs?

 

[gsxr]

Any final word on Russian f8dc4 plugs?

They should be fine. I've not heard of any issues with them.

 

[Oldcar]

Found bosch Russian f8dc4 with broken porcelain.......using dental pic,endoscope and shop vac with tube attached to remove debri b4 I remove the plug.....feeling like dentist doing a dificult tooth operation. .....lol.

They were old plugs thought they were German.....so make sure you never ever use Russian f8dc4...
.

 

[Oldcar]

Pic

 

[Oldcar]

They should be fine. I've not heard of any issues with them.

Was nearly finished installing my new Mbz Beru plugs and Beru wires when I encountered old f8dc4 failure upon removal. The OLD plugs turns out were made in Russia not Germany....THOUGHT THEY WERE GERMAN all this time they were in engine....

 

[Oldcar]

There is really no need for an LH-based M119, especially in stock form, to need anything other than an F8DC4 -- MB branded, Beru, Bosch, or the NGK equivalent.

Plugs for these cars is like motor oil. Just go with a branded product of good quality, and appropriate weight. So many people over-think plugs, and motor oil.

Please see pic of close to final cleanup of failed Russian bosch f8dc4

The second pic is same plug after removal on my chamber of horrors shelf of failed parts

By the way NGK was always my
Favorite plug....do you have a Pic or part number,?

 

[rayhennig]

M119 PLUG
Costs $ 5.50 from the dealership
Made in France F8DU4
Solid tip not screw on

Exactly the plugs I use and have in stock for my 300-24. Have worked well for many years.

And yes, Beru, made in France.

RayH

 

[Oldcar]

Hey R

I'm thinking of trying a NGK bkr4e ..it's the same as ngk bkr 4e-11....only difference is I believe the 11 is pregaped at 1.1 mm

I had good luck with ngk bkr5e
..but want to see a cleaner plug

I also had very good luck with slightly hotter NGK plugs in the past for short trip performance in older cars....but I am aware of course that a resistor plug is a no no.
What are your thoghts?
...............Lol


.






Town town

 

[rayhennig]

I'm thinking of trying a NGK bkr4e ..it's the same as ngk bkr 4e-11.

I'm no expert but those sound as if they are resistor plugs that are not recommended for many MBs, mine included.

If I were to make a recommendation to you, I'd say that you should go down to MB and ask them for the plugs, just as I do.

Good luck.

RayH

 

[gsxr]

I believe the equivalent to F8DC4 would be NGK BCP5ES.

Note that most USA vendors are OOS on this plug (and, most NGK non-resistor plugs). Be very careful when buying any NGK plugs, for some reason there are a LOT of fake/counterfeit NKG plugs on the market (Google for details). Only buy from reputable vendors. Summit Racing claims to have some at $5/ea.

I've never had an issue with Bosch plugs, regardless of COO. YMMV.

 

[emerydc8]

I agree with Dave—I’ve been running the Russian plugs without any problems.

 

[rayhennig]

I’ve been running the Russian plugs without any problems.

I don't understand why Russian plugs are necessary when you can get them just down the road from MB. Not that Russian plugs offend me but in today's climate they might not be available or subject to Donny's tarrifs?

Do I misunderstand?

R

 

[gsxr]

MB only sells Beru plugs. There have been some (rare) reports of problems with the OE Beru.

AFAIK all current Bosch inventory is made in Russia, unless you find someone on eBay selling the older Brazilians or Germans.

NGK is another option if you can find them. Ditto for the discontinued Champion C11YCC shown in the EPC.

 

[rayhennig]

MB only sells Beru plugs. There have been some (rare) reports of problems with the OE Beru.

Thanks for educating me. I did know about MB only supplying Beru and that's why I have a large stock.

But I've never heard of problems. What sort of problems, and when?

R

 

[gsxr]

Thanks for educating me. I did know about MB only supplying Beru and that's why I have a large stock.

But I've never heard of problems. What sort of problems, and when?

It was mentioned in passing a couple of times on this forum. From memory, I think one person reported a defective plug (caused a misfire, due to "open" circuit internally)... another may have reported a cracked porcelain or something like that? I can't recall specifics. So far it's been quite rare, however I don't know how many people are shelling out for the OE Beru since they cost quite a bit more than Bosch aftermarket.

 

[rayhennig]

shelling out for the OE Beru since they cost quite a bit more than Bosch aftermarket.

Mine were about 5€ each, if memory serves. They certainly weren't much more.

But I now see the usual MB chancers wanting 8 or 9€.

I'll ask my son to get a price from his mate at MB in Angouleme. We usually get 20% discount on service stuff.

R
PS:

 

[500AMM]

Found bosch Russian f8dc4 with broken porcelain.......using dental pic,endoscope and shop vac with tube attached to remove debri b4 I remove the plug.....feeling like dentist doing a dificult tooth operation. .....lol.

They were old plugs thought they were German.....so make sure you never ever use Russian f8dc4...
.

@Oldcar, you're probably aware of this already, but I like to add a general comment to that porcelain cracking scenario;
That has happened to me 3-4 times, not on the M119 but back in the motorbike days when spark plugs were replaced more frequently. I recall especially one bike with very tight access to the two inner plugs, and I used a very short spark plug wrench with a rubber grommet inside picking up the plugs. Due to tight access both for tightening and breaking them loose, it was easy to bend the wrench a bit sideways - or in case the wrench was slipping, the porcelain could easily break. So my point is that spark plug wrenches with a rubber grommet pick-up requires correct positioning & stability in use. I still use this type of wrench today, so I don't know whether other types with a spring or magnet pick-up allows more flex.

BTW, we had some discussion about spark plug wrenches in the following thread, post #11 and down. Using a wrench without any pick-up may be the safest way, and use a rubber hose to pick up the spark plugs as shown in that video:

N

Post in thread 'Non Resistor Spark Plug List'

Feb 13, 2023

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?

• nikitino25

• 
• 

 

[R129 UK]

MB only sells Beru plugs. There have been some (rare) reports of problems with the OE Beru.

AFAIK all current Bosch inventory is made in Russia, unless you find someone on eBay selling the older Brazilians or Germans.

NGK is another option if you can find them. Ditto for the discontinued Champion C11YCC shown in the EPC.

Or India:

Post in thread 'Rough Idle When Hot, with Solution'

Mar 21, 2025

Generally I have seen the Bosch-branded F8DC4 plugs made either in Russia, or Brazil. India would be new to me, though perhaps not out of the question.

Here is the proof:

• R129 UK

• 
• 

 

[gsxr]

Well there ya go! India is the new Russia (which was the new Brasil).

 

[gerryvz]

Not a surprise to see the COOs changing over time. Production had moved out of Germany quite some time ago. I know that some plugs were still being made in Germany at the same time they were being made in Brazil (there was an overlap), but that was many years ago.

 

[Oldcar]

@Oldcar, you're probably aware of this already, but I like to add a general comment to that porcelain cracking scenario;
That has happened to me 3-4 times, not on the M119 but back in the motorbike days when spark plugs were replaced more frequently. I recall especially one bike with very tight access to the two inner plugs, and I used a very short spark plug wrench with a rubber grommet inside picking up the plugs. Due to tight access both for tightening and breaking them loose, it was easy to bend the wrench a bit sideways - or in case the wrench was slipping, the porcelain could easily break. So my point is that spark plug wrenches with a rubber grommet pick-up requires correct positioning & stability in use. I still use this type of wrench today, so I don't know whether other types with a spring or magnet pick-up allows more flex.

BTW, we had some discussion about spark plug wrenches in the following thread, post #11 and down. Using a

@Oldcar, you're probably aware of this already, but I like to add a general comment to that porcelain cracking scenario;
That has happened to me 3-4 times, not on the M119 but back in the motorbike days when spark plugs were replaced more frequently. I recall especially one bike with very tight access to the two inner plugs, and I used a very short spark plug wrench with a rubber grommet inside picking up the plugs. Due to tight access both for tightening and breaking them loose, it was easy to bend the wrench a bit sideways - or in case the wrench was slipping, the porcelain could easily break. So my point is that spark plug wrenches with a rubber grommet pick-up requires correct positioning & stability in use. I still use this type of wrench today, so I don't know whether other types with a spring or magnet pick-up allows more flex.

BTW, we had some discussion about spark plug wrenches in the following thread, post #11 and down. Using a wrench without any pick-up may be the safest way, and use a rubber hose to pick up the spark plugs as shown in that video:

N

Post in thread 'Non Resistor Spark Plug List'

Feb 13, 2023

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?

• nikitino25

• 
• 

Hi 500,

Enjoyed Kent's video...I havnt seen a video from him in a while an really like.him!

My plug problem began when holding the extension I was unable to access the sparkplug nut or get on it.....never happened before...the broken porcelain from the insulator was blocking my extension from getting on the nut!

Finally after removing the porcelain and cleaning everything out I was able to get on the nut with the extension.

Thank you for your post it was excellent!