Check engine light on 2002 Mazda Millenia

The problem that causes the check engine light to come on cannot be traced. The diagnosis is multi engine misfire. The dealer has checked and rechecked
but problem still exists. The last time my mechanic changed spark plugs he noticed oil on one of the plugs he removed in the rear side of the engine. He replaced the plug with the rest of them. Could it be that one or more of the spark plugs are sucking oil and causes the misfire? If so what could be the cause of that. Do I need a full tuneup? My dealer recommends replacing te cam shaft pulley beause it’s loose and this may or may not solve the problem. I’m not a mechanic but it appears as if the problem has something to do with the spark plugs sucking oil since the check engine light might go ou for a week or so and then come back on for a while. Lastly is it dangerous to keep driving the car especially on long trips?


“multi engine misfire” is most likely P0300 . . . random misfire

“oil on one the plugs” . . . oil fouled plugs can misfire

It is possible that you have worn rings, valve guides, valve stem seals, etc.

Why would the cam pulley be loose?

Was any work done recently?

I would retorque the cam pulley bolt, check valve timing and make sure timing belt is still good

BTW . . . the only way the dealer would really know the cam pulley was loose was if their mechanic removed the timing cover, I would think

Is this the original timing belt?

If the cam pulley were loose, you can certainly have a random misfire

But why do they already know it’s loose?!