1997 Honda Accord 97 Honda Accord LX Engine Shaking problem

Engine light does not come on. I do not think the engine itself is running rough; otherwise, it will not become normal after I drive a car for a while. Although the timing belt service is due, it should not contribute to the engine shaking problem. This is a comman problem for the high miles vehicle comparing with the new or low miles vehicle. The most of the high miles vehicles begin the enging shaking problem when the driver starts the car, especially in the morning and winter. I just do not know why the engine shakes when it strats after the vehicle reaches high miles, especially in the morning and cold weather. I have replaced the spark plugs. The spark plug is a little dirty with a little white particles/powder and oil. After a change of the spark plug, the engine shaking has a litle improvement. It should have other potential problems. Do you have any idea?

Hi, no oil in the plug holes and never. Spark wires are good. No smell of fuel or raw gas. The timing has not been checked. I think it is a common problem to the high mileage vehicle, engine shaking in the morning especially in the cold weather, but it will be well after it runs fro a while. Have you seen the similar problem?