Platinum plugs & Silicone wires
 

Is running Platinum plugs with silicone wires really a nono? 1990 420 SEL.

How much is a new ignition module again?

I wouldn't run platinum plugs in any 1990 MB, they suck. Use the updated Bosch Copper Pluses. My 1990 300TE was running like crap and I discovered the previous owner had installed Platinums in the engine....I did nothing else but replace the plugs, this was last October and the car has run perfectly ever since. This idiot also had put synthetic oil in it as well. Swapped that out for the real stuff and the oil pressure gauge went from virtually 0 to 3 bar immediately and has remained there ever since. I wouldn't mess with original factory specs. Bad way to fly.....trying to fool mother Mercedes.....

Not trying to hijack this thread into yet another oil discussion, but my 300SE has been running synth Mobil1 10W40 and I've never had an oil pressure issue. Is it possible he just used way too light an oil? The PO switched to the synth, and I have stuck with it just because. Again, my pressure readings are exactly what the book says they should be......


-tp

I've read this from cliffmac a couple of times this week, seems he blames synthetic oil for an oil pressure problem, apparently doesn't understand oil nor that the OP didn't ask about his oil problem.

Plat plugs are considered a no-no as mentioned.

I am not blaming synthetic oil as my 300TE did not lock up or anything, I am simply suggesting that the oil pressure sensor will send a poor signal to the dash indicator. That's all....perhaps the sensor, as installed, is not calibrated for a less viscous oil and thinks there is no oil pressure...Get It?

but generally, I must say, that sythetic oil is bullcrap if the engine is not designed for it. No question, causes way more problems than it solves.

So whether it is synthetic or not is not the issue, and you should post that the previous owner of your car had put the wrong viscosity oil in, not whether it was a syn or dino oil.

Your opinion on syn oil being inferior to dino oil tends to disagree with much scientific data as well as 30years of spectro-analysis by me, and by the airlines as well as many of the manufacturers which were requiring it to maintain warranties.

Jeff, ignore the troll.

It's not the platinum per se that causes problems, but that the plugs are resistor plugs. I don't know of any platinum tipped, non-resistor plugs made for our vehicles. Whoever would make these plugs would make a handsome profit off the "gotta have something better for my car" crowd.

I was reading, no scientific data but on-line stuff, that the platinum plugs didn't create a problem because of the metal used, but because of the mass of metal being that the platinum is such a tiny electrode and that somehow makes it more vulnerable (especially in a reverse-polarity spark in a waste-spark system).

I haven't really looked that much into it, but since good copper plugs work, I've just stuck with that.

Other makes (such as various Audi forums) also tend to recommend not using platinum plugs so I don't really know the source. They have typically been a 60,000mile item for me so I don't work too hard at finding a better way. Oops, reminds me that the Ford just hit 60,000miles on its Bosch copper plugs, better order a set.

Yah, what ever happened to the W9DC plugs? I had a set once and they were fantastic. Suddenly the parts stores around town just stopped carrying them.

I got the same answer from everyone... "Bosch has decided to phase these out"... so I went to NGK's just for the sake of having resistor-free plugs... It does pretty well now, but not the same as the original Bosch non-resistor copper plugs.

-Troy