craig3x

When I first start my 2005 C55 in the morning, the power steering pump whines, and doesn't work very well until the car has been running for a few minutes. Then the whine goes away and everything works fine. Anyone else experience this? Is my power steering pump starting to fail? Any solutions?

RenC55AMG

Mine has been whiny for 10 years; pretty certain they're all like this :P

craig3x

I can't imagine going to dealer in 2005, hearing a whiny PS pump and wanting to buy the car. They can't all be like this. Something must be wrong.

Accidental L8 apex

Mine works great and has never made a peep. My air pump whines on a cold start though.

Khan 55

The air pump whine is normal. The p/s one is not gents. Guys on our forum have drained fluid and filled new. Use agents MB fluid and flush the system out. Best is remove the return hose and cap. Start engine and continue filling new fluid until clean fluid comes out the pipe then have a second person stop the engine. Top the fluid off then rotate steering lock to lock few times whilst the engine is running. Stop engine again and check level. The groan should be gone then. I use this green fluid that comes in a silver tin. Pretty sure its from America but its way better than any other fluid. Cant recall the name though.

APowerX

Use only Pentosin CHF11 fluid and be sure to keep the level topped up. A low level van give the exact symptoms you're describing. Also if you can perform a quick change by sucking out the reservoir and repleneshing it and repeating as necessary to freshen the fluid.