I own a mercedes benz C230 1997. I took it to one of my friends auto repair shop. It was keeping a chirping noise under the hood. He looked and said it looks like the pulley where the tensioner is was bad. So I ordered a pulley from MB parts department. Okay, when I took it to him to put on the car, he was having a hard time getting the screw/bolt/nut off. So he told me to spary it with WD40 for a few days to loosen it. I took it back and he still was having problem getting it off. He say that I probably needed to order the Tensioner behind it just in case he broke the stem when trying to get the nut off. Okay, so I ordered the Tensioner. I took everything to him the other day. He put the new tensioner and pulley on and started the car. He did not test driver it. It sounded okay. When I got ready to leave the shop.it was hot, I turned on the Air conditioner and I started to hear another loud noise unlike the chirping noise we heard before he replaced the tensioner and pulley. I got worried because I thought the belt was coming off. I called him and told him I was turning around and bringing it back. When I pulled up he heard the loud noise and told me to pop the hood. The air compressor was shaking. He told me to turn the air off and it stopped. but I noticed today that it still makes that noise even with the air off. It never did that before he replaced the new parts. He told me it might be because my compressor is going bad. If that's the case, why did it just start to make that noise right after he replaced the new parts? I am starting to think he did not do something right?n Help! This is starting to cost me!!!

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1997 Mercedes-Benz C230 6

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