I have a 2009 159 1.9 JTDm. The power steering started to make a noise. In my non-Alfa cars, I have fixed this simply by checking the fluid level.
I had green fuild in the reservoir and the level was between min and max. I don't know what fluid it was but it was green (GI/R, Synpower, something else,..). Not red.
I live in cold climate. Some owners here recommend Valvoline Synpower
because that works well in cold climate. I thought it would not hurt if I remove old fluid and add some fresh fluid. The Synpower is green, so I assume it works with another green fluid.
I did not bleed the system from the lowest point. I simply pumped out all the original fluid in the reservoir and filled it with Synpower. And next day i did the same again.
But the noise did not go away. It was away for a some time, but then it returned again.
When I opened the reservoir immediately after driving, I noticed that there were bubbles in the fluid. So I decided to remove the reservoir and take a closer look. I found a filter rolling inside the empty reservoir. I don't know why it had got loose, because it looked good. It was not dirty or anything.
The reservoir: Picture
The filter: Picture
I found a thread on the Finnish Alfa Romeo board
about the filter. It says that the filter should be on the return line. Unfortunately, I think the reservoir can't be opened (?) and it is not possible to plug the filter back to where it belongs.
Do you know, why there is a filter on the return line? Doesn't this mean that if there is any dirt in the system it can't get out? It would make more sense to me, if the filter would be on the line that goes to the power steering pump.
I removed the filter that was rolling inside the reservoir and filled the system Synpower. Now my power steering works perfect, no noise, no bubbles.
How important is the filter in the reservoir? Should I worry if the system works, fluid looks ok, and the power steering does not make any noises? I am a person who changes power steering fluid every now and then. If there is any significant dirt in the system, I will see that in the reservoir when changing oil? And other particles will be cleaned from the system when I change the power steering fuilds?