For more info and related parts mercedessource.com/tech-help/...
Replacing spark plugs in the 102 and 103 4 and 6 cylinder engines is not as straight forward as you might think. There are some pitfalls that if not avoided can lead to frustration and even engine damage. Kent shares some of his tips you might want to use when replacing plugs in your own Benz. Applies directly to 190E, 260E, 300E, 300CE, 300TE, 300SE and 300SEL. Principles also apply to other gas engines including older 4, 6, and 8 ( V / 8 ) cylinder.