I changed the plugs recently on my 2012 Lincoln Hybrid, 87,000 miles. Two of the 4 plugs had oil on the threads, one of them just loaded with oil on the threads. The electrode was fine, iridium and platinum tips seemed fine, just oil coating and yellow on part of insulator. So, after a couple of hundred miles I pulled the new plug on the cylinder that was really coated, the new one has a slight coating of oil as well.
So, this engine has never used oil, in fact some fuel dilution as the dipstick will actually rise over the course of a OCI. Now it could be fuel on the threads but feels like oil. No indications prior to plug swap, no misfires, or anything to indicate an issue.
Do I just let it go on a 9 year old car, or assume I have to pull the valve cover and see if a valve or plug seal is bad, or bad ring. To have a tech look at it, well, probably $200-$800 depending.
What would you do? I am assuming that being a hybrid; that the constant starting and stopping of the engine during city driving is not an issue with hybrids?
So, this engine has never used oil, in fact some fuel dilution as the dipstick will actually rise over the course of a OCI. Now it could be fuel on the threads but feels like oil. No indications prior to plug swap, no misfires, or anything to indicate an issue.
Do I just let it go on a 9 year old car, or assume I have to pull the valve cover and see if a valve or plug seal is bad, or bad ring. To have a tech look at it, well, probably $200-$800 depending.
What would you do? I am assuming that being a hybrid; that the constant starting and stopping of the engine during city driving is not an issue with hybrids?