Spark Plugs: Resistor vs. Non-Resistor - PeachParts Mercedes-Benz Forum

danwatt · #1 08-21-2007, 12:52 AM

Have you considering doing a search and reading one of the 1 million threads on the subject? Honestly if I had a dollar every time this was topic was explained to somebody...

jodiedog · #2 08-21-2007, 01:35 AM

All I know is this.I have a 1996 E320,Car ran like crap.Changed plugs to Bosch Platinum 4's Ran worse.Changed to Bosch Copper Non Resister Plugs F8DC4,about $2.00 each,runs like new again.Did nothing but changed to non resister plugs.

petaling · #3 08-21-2007, 10:46 AM

How about for my m103,Mercedes dealer says only RESISTOR plug available,and it will be okay to use them.?????This apparently is sanctioned by Mercedes Canada.

So before they say it's not okay to use resistor plugs,now they say it's okay?

I searched high and low and found some non-resistor plugs in the ebay.co.uk.Now they are in my car.
Next time around,there wont be anymore?

MB-Dude · #4 08-21-2007, 11:15 AM

Quote:

Originally Posted by jhodg5ck

IMHE, I've had more customers coming in who had recently switched out to resistor plugs only to find their fresh cap/rotor/wires in a sad state.. Namely lots of arcing in the cap/rotor and wires that are no longer w/ in spec.

The WIS states on many occasions that 5Kohms is the maximum total ignition resistance, beyond that they state that damage to the ignition componentry will result.

Were it really a non issue and simply a cost matter I do not think the service literature would state the above...

Just my 2.

Jonathan

I, too, have heard of this situation through legend and folklore. Obviously, as a mechanic by trade you can speak from direct experience. Though I’m not sure how the arcing can be worsened in the distributor/rotor interface simply by using resistor plugs.

However, your point about the WIS stating a maximum of 5Kohms resistance is interesting. While I do not have the WIS available to me, to does provide another piece to the explanation puzzle.

Quote:

Originally Posted by danwatt

Have you considering doing a search and reading one of the 1 million threads on the subject? Honestly if I had a dollar every time this was topic was explained to somebody...

Yes, I have searched… and searched... and searched. The problem is the sheer amount of emotional flotsam on the subject. But more importantly, there is the possibility that as time goes on, opinions and capabilities change. MB Engineers change direction as any other engineering team does. They and their vendors make advances that allow backwards compatibility. Further discussion may bring forth a new revelation or hard, objective data that explains the old method. Continual questioning is a natural tendency for us engineers. Sorry. At least this thread gives the Diesel guys something to chuckle about!

Quote:

Originally Posted by jodiedog

All I know is this.I have a 1996 E320,Car ran like crap.Changed plugs to Bosch Platinum 4's Ran worse.Changed to Bosch Copper Non Resister Plugs F8DC4,about $2.00 each,runs like new again.Did nothing but changed to non resister plugs.

Interesting. My experience – anecdotal like yours – was that when I installed Bosch Platinum+4 plugs in an already good running SL600, that the engine ran better. I freely admit my experience is a subjective statement. But it does show that people can have different experiences with the same product. For the record, I did take out the Bosch Platinum+4 plugs and installed standard, off-the-shelf OEM parts. It was an action based upon emotion, as opposed to data.

Quote:

Originally Posted by petaling

How about for my m103,Mercedes dealer says only RESISTOR plug available,and it will be okay to use them.?????This apparently is sanctioned by Mercedes Canada.

So before they say it's not okay to use resistor plugs,now they say it's okay?

I searched high and low and found some non-resistor plugs in the ebay.co.uk.Now they are in my car.
Next time around,there wont be anymore?

Hmmm… Playing the Devil’s Advocate, dealers do not always provide accurate information. Then again, they may know something we don’t. Regardless, are you saying the dealer could not supply the ‘factory’ spark plug for you vehicle? Doesn’t make sense.

Again everyone, I’m not stating one plug is better than another or that resistor plugs are better than non-resistor. I only want to find conclusive, objective data that says one way or another. This is the same discussion that many of us had when synthetic oil was first introduced. Now look – it’s the standard! And how many of us poo-poo’d synthetic when it first came out, simply because it was ‘different’. Same could be for plugs. Discussion is always healthy.

manny · #5 08-21-2007, 04:34 PM

Quote:

Originally Posted by petaling

So before they say it's not okay to use resistor plugs,now they say it's okay?

Please don't generalize.
M-B specifies resistor plugs in some engines & none-resistor plugs in others.
So, if you want to make your own rules go for it ( and live with the consequences ).

JamesDean · #6 08-21-2007, 09:57 PM

this ***** is confusing. heres a question: why doesn't someone just ask mercedes? like their engineering team. heck I'm gonna email them and see what their official response is.

roar.

email sent to the Classic Center. We'll see what they say...

280EZRider · #7 08-22-2007, 01:05 AM

A simple question: I have installed Bosch platinum plugs #4020 in a 110 engine - there is no "R" in the number. (I could not care less about radio interference as all staions in the SF Bay Area now suck anyway). So are these plugs resistors or not?

petaling · #8 08-23-2007, 09:07 PM

Quote:

Originally Posted by manny

Please don't generalize.
M-B specifies resistor plugs in some engines & none-resistor plugs in others.
So, if you want to make your own rules go for it ( and live with the consequences ).

Have you tried getting non-resistor plugs from the dealer for a 15 yr old W124?Last time I went to the dealer Mercedes Benz Markham branch,they gave me RESISTOR plugs?
10 years ago,they told me resistor plugs were bad for my car.So what gives?Are they trying to kill my car and sell me a new one?
I declined and got mine in the UK before I knew about their avail here from this site.

Manny if you know of any source of non-resistor plugs in Ontario,please let me know.!!!!!!!!!!!!

zcc · #9 08-21-2007, 11:47 AM

Quote:

Originally Posted by danwatt

Honestly if I had a dollar every time this was topic was explained to somebody...

It sounds like Larry Luffer. "I wish I have a dollar everytime I say that" LoL

Hatterasguy · #10 08-21-2007, 01:29 PM

Well these days they use super expensive platnum plugs.

I doubt that when building the M119, or the M120, or the 600 Pullman's, they gave a flip about saving a couple cents on spark plugs, when they spent so much money on wires!

Or in the case of the Pullmans $1,500 seat switch's!

I think some engineer got a little to much freedom back in the day and built an ignition system around these cheap plugs, and they just followed his lead for years. AFAIK all gas MB's called for non resister plugs until the M112/113 came out in 1998.

The FSM is pretty specific about what you can use, I prefer not to backyard engineer things. More so when the part they want you to use is the cheapest! Why should I go out of my way to research if a $5 plug will work, when they tell me to use the $1.50 ones in the manual?

You can do whatever you want with your car, and if from your experiance platnum plugs run fine in these go for it. But from my experiance I have never had problems doing what the FSM says to.