Has anybody ever had problems with their oil level sensor, and have they replaced it. My 98 ML320 will blink between "OIL HI" and "-2.0L" everytime I drive it. I took it to the shop, and they want $460 plus an oil change to fix it - says it needs a new oil level sensor. I thought about getting one and installing it myself. Has anybody tackled this one - any special tools or techniques needed?