The steering makes noise when first starting like a moaing noise is it low power steering fluid
Noise on 2003 Mercedes-Benz ML320
Groaning sound when turning the steering is usually a sign of low power steering fluid. The system should not loose fluid unless there is a leak from the steering pump, steering rack, or pressure hoses. If the fluid level is OK perhaps try flushing the power steering fluid, install new fluid and perhaps see if a product called Lubegaurd is comaptable with Mercedes fluid. Lubegaurd is a great steering fluid additive for many other cars.