Misfires under load (acceleration) can be caused by the valve cover gaskets leaking oil into the spark plug wells shorting the spark plugs to the cylinder head. New spark plug wires will be needed and the valve cover needs to be resealed.Google+
Car Problem Reports
Mazda Millenia Misfires Under Load
Mazda Millenia Problem
Engines Affected: 2.3L V6 Supercharged, 2.5L V6
Average Mileage: 154,846 mi (75,000 mi - 230,000 mi)
Visitor, 1995 Mazda Millenia, 2.5L V6, 75,000 mi
Valve cover s leaking oil into plug wells shorting out spark plugs
Visitor, 2002 Mazda Millenia, 2.5L V6, 115,000 mi
Misfire in the 3rd cylinder, oil found in the spark plug wells, oil leak from the valve cover. I took the car to the shop and they will replace the valve gasket for $400, hoping that could solve the problem
Visitor, 1999 Mazda Millenia, 2.5L V6, 175,000 mi
Check engine light came on and started blinking and then it started to sputter. Checked it out with the computer and came back three codes PO400, PO404 and PO406. Cylinder six is misfiring.
Visitor, 2000 Mazda Millenia, 165,000 mi
Car keeps dying on me! runs great in morning come home from work cant make it home.
Visitor, 2000 Mazda Millenia, 2.5L V6, 123,000 mi
I was just doing some routine maintanance changing the plug wires and spark plugs and when i got to the back 3 spark plugs i noticed the first one was dripping with oil and oil was puddle in where the spark plug goes. The job calls for 3 and a half hours labor. Does not sound fun.