An oil leak can develop from the spark plug tube seals. Excess oil in the spark plug tubes can result in engine misfires and illumination of the Check Engine Light. Our technicians tell us that removing the valve cover and replacing the tube seals and cover gasket is necessary to correct this concern. Oil damaged spark plugs, ignition wires, and ignition coils will also require replacement.
Car Problem Reports
Subaru Forester Worn Out Gaskets Allowed Oil to Seep Into Spark Plugs
Subaru Forester Problem
Engine Affected: 2.5L 4 Cylinder
Average Mileage: 102,071 mi (51,000 mi - 160,000 mi)
Visitor, 2003 Subaru Forester, 80,000 mi
Oil leaked into spark plug tubes. Destroyed coil and wires. Replaced all.
Worn out spark plug tube gasket and or valve cover gasket allowed oil to seep into spark plugs, which damages the spark plug wires. Needed to replace the spark plugs, wires, & gaskets.
Visitor, 2004 Subaru Forester, 2.5L 4 Cylinder, 160,000 mi
This is the problem...now need to fix
Visitor, 2009 Subaru Forester, 2.5L 4 Cylinder, 55,000 mi
Oil Leaked into Spark Plug Tubes causing misfire on Cyl 3,4. This was repaired then CC showed bad. After replacement of CC under warranty misfire problem is back. Dealer replacing Coil Pack (not under warranty).
Visitor, 2010 Subaru Forester, 2.5L 4 Cylinder, 59,000 mi
Noticed gas mileage declining. Thought the spark plugs might need changed, getting close to the time for it anyway. I wanted to check the plugs but found oil in the plug wells. I put it back together and I am persuing factory warranty replacement for all seals that could be contributing to the problem. Not sure if this will be covered but it seems like it should be part of the 60k powertrain warranty.
Visitor, 2002 Subaru Forester, 2.5L 4 Cylinder, 155,000 mi
Oil was leaking int spark plugs....eventually caused misfire (flasning check engine light) Replaced seals/gaskets, plugs, and wires.
Visitor, 2006 Subaru Forester, 2.5L 4 Cylinder, 80,000 mi
Engine misfire related to oil leak filling spark plug tube, replaced valve cover gaskets
Burning oil small in passenger compartment. Oil leaking onto manifold from valve cover/spark plug gaskets. Replaced valve cover/spark plug gaskets. # weeks later problem returns. Bringing back for re-evaluation.
Visitor, 2004 Subaru Forester, 2.5L 4 Cylinder, 93,000 mi
Not yet fixed....but during routine replacement of spark plugs found oil getting past tube seals and putting light coat of oil on wires. No oil in plug cylinder or on plug. Replaced spark plugs and cleaned wires. Will keep eye on it for now.
Worn valve cover gasket allowed oil to seep into spark plugs, ultimately shorting out the ignition coil (that's when the check engine light went on). Had to replace all--$1000! Pretty unhappy.