Mercedes-Benz ESprinter Rattling Noise

I have a 2007 Kia Sportage. It was raining today, but my car drove fine. When I exited the highway I had to stop at the stoplight, however I couldn't help but brake hard. There was some grinding and sliding. But not too bad, so I thought. When I accelerated no issue. But the first thing to go was air conditioner. I didn't think much of it besides that my air conditioner went. After driving for awhile, my car started making rattling noises. When accelerating it gets louder. When I'm not accelerating, its a bit more quiet but not by much. I don't know what to do. I have a wedding coming up and I would hate to have to get money from that pot just to play the guessing game. Please help me.

I have a 2007 Mitsubishi Galant. The water pump went out a couple of weeks ago. I took it to NAPA and they replaced the Water Pump. The day I picked it up I noticed kind of a rattling noise when I accelerate hard. I have to slowly accelerate for the noise to not be heard much. The noise is heard and felt on the right side of the car. Thats what I do now anyway for fear that something will break. When I am over the speeds of around high 40's and up you cant hear the rattling, it is just when you accelerate hard on the pedal. I took it back to NAPA last week and they first told me it was the tensioner, NOT IT. Then they told me it was the Axle, NOT IT either. They are trying to tell me now it is the transmission. However the transmission seems fine to me. The car has 125000 miles but Transmission has always ran good. And I had never heard the noise before the water pump went out and the noise started the day I picked it up from NAPA. Any thoughts