Ford Focus 1.6 100cv- vibrations and consume oil

Thanks in advance. I own a Ford Focus 1.6 100CV of gasoline, Zetec motor of the year 2000, with 245,000 km. After excessive loss consumption using 5W-30 oil I recently passed to 10-40. Without noticing notable improvements (I have reached a liter at some occasion after a 500 km trip). Today I have noticed small vibrations and lack of power, as if the engine were in three times instead of four, with the consequent difficulty in taking speed. Arrested and idle is not seen abnormal. I have noticed and at fourth speed at 100 km/h the engine was at 4000 rpm. I have tried to change the spark plugs and I have found the upper part of where they are housed with abundant oil. Enough to soak two napkins. I have dried it, I have changed the spark plugs for new ones, but I have not achieved anything. Does anyone have an idea what the breakdown can be? Thank you very much again, Adolfo

In what state the spark plugs came out, because for what you say you are burning the oil not by throwing it

Thanks for your answer. From what they tell me in the concessionaire, the lack of power and vibrations is of the ignition is due to failure of the coil and one of the spark plugs.
When I have taken them apparently, they are fine. I have not noticed anything abnormal within the wear in the electrodes. And if it is true that one of them in the ceramic zone near the nut, had an atmosphere of roasted thick finger.
I have not found any relationship with oil, because as soon as it endures several weeks, as in a couple of days descends from the maximum to the minimum. Or on a 500 km trip, he has spent it and on the return of the same trip, no.
The oil that I have observed in the area where the spark plugs are housed, have blamed it in the concession to the rocker lid.

If it is fine if the spark plugs do not go out with a black cosra, the oil does not pass to the camera, if the escape by the lid were the cause of the consumption of oil to be noticeable that is to say that it would have to escape a lot, anyway the prosecutor is thus sealing leaks and trying, it has seen how it goes, the lack of power if the coil can be nothing to say and the irregularity of the engine I would go. Tell us how you are doing.

I have picked up the vehicle and have replaced the rocker lid, the coil, the spark plugs and 2 of the spark plug cables. The car goes very, very well. I remain intrigued by the high oil consumption that it has and how irregular it is, because it does not lose it. Thanks, greetings