I recently had the dreaded engine light flashing , car started shaking uncontrollably.

Took this to the garage who advised coils had to be changed . Changed all 8 coils as mechanic found some were broken. He suggested that broken pieces of ignition coils might have gotten into valve cover and that needed to be removed and cleaned. This was for inlet and exhaust valves for all 8 cylinders. After this EGR valve and EGR pump was replaced as this was also broken.

Problem still persists and mechanic has found low compression and oil in combustion chamber. Oil is coming up to spark plugs.

Engine needs to be removed for inspection and position , rings and steam seals etc to be replaced. Any idea what has caused this and if complete engine overhaul required. I have suspicion that wrong oil was used during major service ..

Mileage of car is 117,000 km