BOSCH 4+ SPARKPULGS ON M103 ENGINE?

[300EVIL]

IVE HAD A FEW MECHANICS TELL ME THAT PLATINUM PLUGS WERE NOT GOOD FOR MY ENGINE IN MY 300E BUT, THEY COULD NOT GIVE ME AN EXPLANATION WHY.
COULD SOMEONE PLEASE ENLIGHTEN ME ON THIS REASON.
THANKS,
ADAM

I don't have an answer to your question, but I do have platinum+4 in my 2.6 liter. They have been in for about 10,000 miles. They work fine. Are they better than the copper bosch I replaced? Probably not. I can't really tell any difference one way or another. I would just use a regular plug if I were you. Save your money.

There are two potential problems with these plugs. The worst of which is that they have been known to break, leaving indigestible particles in the upper end of your engine.

The more likely problem is the fact that due to the expense of the platinum material, the electrode is very thin, creating a thin spark. This can result in a rough idle.

Before I knew this, I ran a set of the platinums about 70,000 miles. They did produce a rough idle.

I now use copper Bosch plugs set at about .038. They give me a much better idle. The only down side is changing them about every 30,000 miles instead of screwing them in and forgetting about them.

Good luck,