Beru Plug Replacement 4 Defunct Bosch H9DCO - My Story
 

Several months ago it was learned by more than one member here that Bosch had decided to eliminate the production of non-resistor plug numbers H9DC & H9DCO. These "non-resistor" plugs were designed for use in many MBs made throughout the 80s and early 90s. The word has always been that many of the MBs from this era required a "non-resistor" plug. As far as I know, all 103 motors use them and if I'm not msitaken, the 102 line as well. There may be others.

Beru(a German parts mfg.) has made the single electrode equivalent for the Bosch H9DC/H9DCO for years. Some MBs once shipped from Germany with them in the motor.

The Beru plug in question here is -> 14 K-7 DFUO (Z18). It's a single electrode plug designed like the Bosch H9DC/H9DCO and again, is the equivalent of said Bosch plug(s).

My research revealed that there was ONE source for this plug in the U. S - kingsborne.com - owner - Warren Hartley. I contacted him on 6/12/06 and order a set. He told me it would be 7-10 days. 3 weeks passed - no plugs. Contacted Warren via email and got the "7-10 day story" again. 2 months passed and still no plugs. Contacted Warren again and no response. He stopped responding to me. I wasn't to concerned as he had not charged my CC account.

Checked the mail box upon returning home last Fri(9/9) and guess what? - 6 Beru plugs sittin' in the mail box - shipped from Kingsborne in California. Only took 3 months - not bad - huh?

I emailed Phil awhile ago and suggested that he load up on these for forum members. Bosch's "resistor" replacement for the H9DC/H9DCO aint' gonna fly if you believe all that's been written about the "non-resistor" requirements for 103 motors.

I'd also like to refer to something posted in another thread. The pointer to it is further down. In it, a member lists several U. S Dist. for Beru plugs. They are all wholesalers with the exception of Kingsborne, and will not sell to individuals.

You may still find the Bosch H9DC/H9DCO listed at the various WEB seller sites, but I have heard first hand from a few diyers that they've received the new Bosch "resistor" plug and not the H9DC/H9DCO plug after ordering the Bosch H9DC/H9DCO. If you can find the Bosch "non-resistor" plug - congratulations. The source is drying up. I've never seen the Beru single electrode equivalent listed at any WEB seller site.

Sorry for what may appear to be rant, but I wanted everyone here to know one persons expereicne in this matter.

http://www.peachparts.com/shopforum/tech-help/133719-where-buy-beru-plugs-usa.html?highlight=Beru

At Beru Web Site H9DCO translates to Beru 14 K-9 DUO
Same thing in W124 maintenance CD
http://www.beru.com/english/produkte/produktident.php

Beru contact:
http://www.beru.com/english/handel/international/adresse.php?id=h&country=USA

This won't get you anywhere. The Beru dealer in Illinois sells to Kingsborne. You cannot order from the Illinois Beru dist. listed in your post. They'll point you at Kingsborne or the others that are listed in the URL at the bottom of my first thread and the "others" are whosesalers - they sell only to retailers or shops - not diyers. I called everyone of them. Presently, Kingsborne.com is the only U. S. source for diyers unless you know of someone who doesn't advertise on the WEB & who just happens to have an old stash.

I contacted Phil. All of his contacts have dried up. He's going to call both the Illinois dist and Kingsborne. With his bulk buying power, he may be able to generate more enthusiam than I got out of a "6 plug" order.

A good solution is NGK BP5EFS

Arthur - that's what I've been waiting to hear! I value your opinions and to HELL with the 3 month wait for Beru plugs! Problem solved.

Knowing this made coming up with a plug cross-ref site easy:

http://www.spark-plugs.co.uk/pages/technical/boschd6b-w4e2.htm

Thank your sir!

Hate to say it, but since Bosch plugs have been made in India, I have had nothing but troube with them
The last 2 sets I put in my 113 [ Bosch Supers, W8DC .plain Jane plugs] 4 out of the 12 had problems with the insulators actually turning in the plug casing.. they were replaced by bosch and the new ones did the same thing within 1K miles . Could actually spin the insulators by hand in the case .
When I brought them back , the counter guy knew it right off the bat, so I was not alone... but Bosch siad they never heard of such a problem. Said I must have torqued them incorrectly... Yeah, Right Pal, I have been changing plugs on Autos and Aircraft for 40 some years... get lost !!!!!
4 out of 12 was enough for me.............
Changed to NGK and problems solved....................

well, i've talked to bosch several times.
they say yes, they are resistor sp plugs
but not enough to be an issue. they said
we will not notice any differance.

george

That's a 3/4" reach gasketed plug with a 13/16" hex. The M103 requires a .708" reach taper seat plug with a 5/8" hex.

The NGK TR5 is a resistor plug equivalent to the HR9DC. NGK does not offer a non-resistor verision equivalent to the H9DC.

If one wants to stock up on H9DC or H9DC0, try dealers, but their prices are probably higher than the aftermarket - back when the aftermarket actually had them.

I found one set of H9DCs on the web and bought one at a dealer. I also have two 15K mile used sets that I ran through a spark plug cleaner that are serviceable for at least another 15K miles. At the rate I'm accumulating mileage I should be good for the duration...

Duke

well, you folks sufficiently scared me to order 6 more of the bosch from Arizona ******** with this months order... i have 6 new ones sitting in the shop... but with two cars, i decided to go ahead and get 6 more

h8dc @ 1.13 each


http://www.***************/search/productx.aspx?sid=altpr2m3uw0oew55ew0vapnt&makeid=800016@Mercedes&modelid=1193600@300CE&year=1989&ci d=25@Ignition%20Parts&gid=7212@Spark%20Plug

lee... I ordered from them 4 plugs for the 190E and they came and its the resistor type.

Should I worry? This is going into a M102 2.0 engine.:confused:

<<That's a 3/4" reach gasketed plug with a 13/16" hex. >>

Where did you get that info??

I can not find the specs.
Tnx

MBSHOP - I know you do this for a living and I'm not an electronics engineer, but what Bosch is telling us about not noticing any difference violates fundamental rules of electricity.

By switching to a resistor plug, they've modified the "ohm" side of the equation -> voltage - current - ohms.

A given amount of each of the 3 creates a specific circuit. Alter any of the 3 and the circuit changes.

I fail to see how we won't notice any difference. It would be nice if someone with a legitimate electronics background could contact Bosch and have someone there with same background explain how this is going to work.

I hoping Duke2.6 makes the call to Bosch - graduate degree in Mechanical Engineering. I suspect Duke could weed thru their story and decide if it's for real.

Once again - my 2 cents.

It kind of depends on relationship between wires and plugs.

Germans in past have liked nonresistor plugs and resistance in wires/plug connectors.

If a change to resistor plugs is accompanied by change in plug wires/caps, result can be the same.

The reason Benz prefers plug resistance in the connectors rather than the wires is b/c the R factor is equal to all plugs... with R wires , the OHM is per foot of wire and no wires are the same length.
Solid core wires w/R plugs will work , but R plugs w/R connecors is too much R factor.
Try R plugs on a 104 HFM/SFI waste spark ignition system ..common running faults/complaints.....samre goes for plats on these systems b/c the series spark has to jump out of polarity on the second plug, meaning from ground to the electrode...........Bosch Super , copper core work best here. And they are cheap...

i don't know what the 102 engine takes... probably non-resistor as well...

http://www.***************/search/productx.aspx?sid=c0sou055xgtkwayad3c0y455&makeid=800016@Mercedes&modelid=1192621@190E&year=1987&cid =25@Ignition%20Parts&gid=7212@Spark%20Plug


probably in the owners manual...

there may be a lot of hype here on this one...

any non-resistor may work well... you just NEVER here of problems with Bosch copper core