Jaguar Repair: 1987 XJ6 Jaguar, crankcase pressure, plug holes

Question
What causes oil to come up around the spark plugs when the car is running? There is oil setting on top of the engine in all of the spark plug areas. Thanks.

Answer
Hi Lucius,
To start with, any plug that has oil seeping around it means that spark plug is loose or missing it's gasket. Most spark plugs torque to about 25 ft lbs. So first check that they have gaskets on them and then torque them all to 25 ft lbs.

Then you need to check the breather screen on the front of the head and put new gaskets on the cam covers as that is a common cause of oil puddling in spark plug holes on 4.2 Jaguars.

The breather screen gets clogged and thus you get excess crankcase pressure which then starts leaking out gaskets and the cam covers are often the first to show it. It is difficult to see the oil leaking down the sides of the aluminum head but it then collects in the spark plug holes.
Howard