I changed the spark plugs with the bosch platinum +4 and then the trouble started. The plugs turned black in about five minutes and the car did not run well. I replace the three plug wires but not the ones that sit directly over the plug. Still rough. then put all original back in and still rough. Please HELP ME!!
Thanks Neal snipped-for-privacy@cfl.rr.com
You may have mixed up the wires to the plugs: i.e. #4 is now on #3 spark plug, for instance, easy to do on this engine, especially when changing wires.
The other possibility is a bad coil unit. Some shops change the three coils as a matter of course, about $12 each on the internet.
If it wasn't rough before then you need to review everything that was done; there's a mistake; it's not due to the spark plugs - unless they are incorrect for this engine.
I recently had a similar adventure with my '97 E320 (straight six). First thing #2 coil's hold down screw broke and had to be removed with an Eazyout, then a new Champion plug slightly misfired when cold so I removed them and checked their gaps, .032" OK, bought new seals, put it back together and it still misfired somewhat when cold. Then I installed the Bosch platinum +2 and it now runs perfectly.
Bosch Super copper core run best on 104s.. We use NO other. The problem on these ignitions is the 3 coil connector resistors under each coil. Yoy can not mix up the #3 and 4 plug wires .. as 2. 4. and 6 do not have wires , they are coil dirrect through a resistor connector.
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