Audi Tt Engine Oil Level Sensors Available Here. Engine oil level sensors provide information to you about one of the most important fluids in your vehicle. Engine oil lubricates nearly every important moving part in your vehicle, from the pistons to the camshaft. It keeps everything from overheating or breaking, extending the life of your engine and permitting its operation in the first place. Oil is so important that certain manufacturers allow their engine oil level sensors to prevent your vehicle from starting under certain conditions. Advanced failure of the sensor is also known to trigger this failsafe mechanism, keeping you from going anywhere. Stay on the road: make sure you get a faulty oil sensor replaced at the first signs of trouble.