Hello,

If anybody is in need of non-resistor spark plug for your mercedes I have just ordered some from BERU. Here is the link, $3 each..................
US Distributor of genuine BERU products -http://www.beruparts.com

They are located in San Marcos California and the Tel# is 800-643-0375

They had to order from Germany but are listed in their stock as current and available.

My handbook for the Mercedes 300ce/m103/w124/1989 says I need the following plugs in my car..........
1]Bosch H9DC, H9DCO, or H9DP
2]Beru 14K-9DU, 14K-9DUO, or 14K-9DPU
3]Champion S12YC, or S12YCC

Good luck:

Gavinbr

There are still some vendors with new old stock Bosch on the shelf. I got a set last Spring. Probably should have bought two sets.

Just google HD9CO or whichever you are looking for.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

I have seen reference to not using resistor plugs before. The dealer has always given me I believe hr9dco plugs resistor. I change them about every 30k. Is there a reason not to use resistor plugs?

Because they are out of the non-resistor ones.

Denso T20EPU are a great alternative too.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

I will get iridiums for Christmas

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

the additional resistance of the R -type plug causes performance and idling problems ,not so apparent till you install the correct non- R plugs
ad

Are they more that about 2 or 3 $ or € each? If so, save the money and spend it on Christmas drink.

And no resistor types either, I hope.

R

I don't have the part number on hand but on all the vintage stuff we work on we use NGK non-resistor plugs, had great luck with them and they are easy to find.

IIRC its BP5ES and BP6ES.

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68 280SL - 70 280SL - 70 300SEL 3.5 - 72 350SL - 72 280SEL 4.5 - 72 220 - 72 220D - 73 450SL - 84 230GE - 87 200TD - 90 190E 2.0 - 03 G500

Nissan GTR - Nissan Skyline GTS25T - Toyota GTFour - Rover Mini - Toyota Land Cruiser HJ60 - Cadillac Eldorado - BMW E30 - BMW 135i

I need iridiums with my nitrous

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

Yep, that's what I use.

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1988 Mercedes-Benz 300E W124 M103 California Emissions/Controller

M103-12V uses the NGK BP5EFS

The 6 is a step colder then the 5...
NGK is counter intuitive in their heat range numbering...higher the number, the colder the plug.
Also have the out of production Beru S1K non resistor solid silver electrode plugs that I will be trying out in place of the NGK's...

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http://i19.photobucket.com/albums/b1...c/GOWIDE-1.jpg
1971 280SL ROADSTER
1988 300CE TWIN TURBO WIDEBODY
1994 E320 CABRIOLET
1999 C43 AMG
2005 G55K AMG
2008 CLK63 AMG BLACK SERIES

I have changed plugs in my M103 many times, but I also am getting old enough that my memory is not serving me well.

I remember 10 or 12 years ago Benzmac (Donnie) recommending the Bosch plug and closing the gap a little tighter than the factory spec. I have done that with every plug change since that time and it improved idle quality and general performance. Now, however, I can't remember how tight. I THINK I've set them at .032" but I don't remember for sure.

Even though I'm old, I still have a great memory. Problem is that it's kind of short.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

I'm also old in my 60's.....your .032" or .80MM gap is just fine

From NGK:

3. Gapping
Since the gap size has a direct affect on the spark plug's tip temperature and on the voltage necessary to ionize (light) the air/fuel mixture, careful attention is required.
While it is a popular misconception that plugs are pre-gapped from the factory, the fact remains that the gap must be adjusted for the vehicle that the spark plug is intended for.
Those with modified engines must remember that a modified engine with higher compression or forced induction will typically require a smaller gap settings (to ensure ignitability in these denser air/fuel mixtures).
As a rule, the more power you are making, the smaller the gap you will need.

A spark plug's voltage requirement is directly proportionate to the gap size. The larger the gap, the more voltage is needed to bridge the gap. Most experienced tuners know that opening gaps up to present a larger spark to the air/fuel mixture maximizes burn efficiency. It is for this reason that most racers add high power ignition systems. The added power allows them to open the gap yet still provide a strong spark.
With this mind, many think the larger the gap the better. In fact, some aftermarket ignition systems boast that their systems can tolerate gaps that are extreme. Be wary of such claims. In most cases, the largest gap you can run may still be smaller than you think

http://www.ngksparkplugs.com/techinfo/spark_plugs/installation.asp

__________________
http://i19.photobucket.com/albums/b1...c/GOWIDE-1.jpg
1971 280SL ROADSTER
1988 300CE TWIN TURBO WIDEBODY
1994 E320 CABRIOLET
1999 C43 AMG
2005 G55K AMG
2008 CLK63 AMG BLACK SERIES

Nice write up on gapping,I had wondered why NOS said to close the gap to .030

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1999 w140, quit voting to old, and to old to fight, a god damned veteran