I ahhangedd out thhee plugs on my 86 190e because it was idiling roughh. Found that the porcelin part of the plug thhat surrounds the electrode had only half remaining. The other part must have broken off! What kind of damage could this do? I know it's been running this way for a couple of weeks. I put new Bosch platinums in, so now it runs better, but I'm still worried. It hesitates when it's started in the mornings, I think maybe a new cap and rotor button may be in order. The engine only has about 80,000 miles on it.