1999 Mazda Millenia Q&A
1999 Mazda Millenia Question: There is oil in my 6th cylinder and the spark plug can not fire.
Need to determine if the oil is in the spark plug hole because of a bad valve cover gasket spark plug seal or if the oil is really in the cylinder. So, first do a compression test, should be at least 140 psi in the cylinder in question, then fix the oil leak and get a new wire with a new plug boot and new plug and test. Most of the time when I see this, it is a leaking spark plug oil seal that soaks the plug wire and boot, which causes the spark to short to ground and bypass the plug. - dandd