Q: Car shakes and stutters during acceleration - 2001 Toyota Echo

As I was reading this I was thinking spark plugs, but you said there was a couple CENTIMETERS of translucent yellow oil? I can’t even imagine what must be happening inside the engine to completely cover spark plugs. I would immediately pull all the spark plugs and compare them to a chart you can easily look up on the internet by searching for "spark plug chart". While the plugs are out of the engine, use a bright flashlight to look down into the cylinders. If you are seeing liquid, smell for gas. If it isn’t gas, then its either coolant or oil. I have a ball of cotton string, and in this situation, I would use it to figure out what fluid that is.. (you can use a shoelace if you have nothing else) feed some sort of absorbant but non-linty sting down into the cylinder to absorb some of the fluid.. pull it out. If it doesn’t smell like gas, and it isn’t oily, it’s coolant. If its coolant, the head gasket is blown. if its oil, there is likely piston ring failure. If there is no liquid in the cylinder, change the plugs and make sure they are gapped properly and give it another shot. If you find you are needing assistance with this, consider a certified technician from YourMechanic who can not only replace your spark plugs but also diagnose the leaking.