87 190e 16V Water pump failure symptoms

[Flippu10]

I have a shrieking sound coming out of the area around the drivebelt. It has progressively gotten louder. It starts making the noise a few minutes after the engine is started. I thought at first the belt was loose. I tightened the belt a little bit but did not help any. After listening closely, it sounds like it's coming from the water pump. Has anybody have any experience similar to this? Is it the water pump? What does it take to replace a water pump?

Another thing, when I tightened the belt, I'm not sure if I overtightened. The marker is broke. How can I check? Any advice.