Discussion Starter · #1 ·
Help, I want to find a plug that works in my 420 SEL, I just installed a new set of Bosch super WR8DCW plugs and the car ran fine for a day or so. I went to run it this morning and it was shaking like a bag of crap and wouldn't even drive off. I pulled the plugs and they were black, one of them was completely dead, no spark at all. I put in one of my old plugs, cleaned the others and it now runs fine. The temp here is cold, in the teens at night and I don't know if these temps need another temp range of plug or not. Advice is appreciated.