Hi im writing you all to see if someone can help me. Im experiencing a misfire in my volvo so i decided to take it to the mechanic. He put a scanner and it was giving a code that was telling that one of my ignition coils was failing. So i decided to have that check and when they checked they find out that the sparkplugs and ignition coils has engine oil all around them. So they remove the valve gasket cover and find out that some o rings around the spark plugs was damage and they replace them. Now i dont have any oil leak to the sparkplugs or ignition coils but im still experiencing the misfire. The mechanic sugested that it could be a problem with the cables that connect to the ignition coils. I will take it to an electromecanic but before that i would like to know if there could be another cause for that misfire. (Ignition coilds and sparkplugs was replace too during the repair) sorry for my bad english.

 

with the oil cleaned up, new spark plugs and new coils, the only remaining possible cause is the wiring harness to the coils. Check the connectors to make sure there are no cracks and they seat and connect properly. You may be able to clean and seal the connectors but it may be better to invest in a new harness. I just did this for my 00 S40