C32 AMG, C55 AMG (W203) 2001 - 2007

P0300, P0303, Loud noise when in gear?

Old Feb 1, 2013 | 01:21 PM
  #1  
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From: Grapevine, Texas
2004 Capri Blue C32
P0300, P0303, Loud noise when in gear?

Hey everyone,

I haven't posted in a long time, because frankly I haven't been having problems. Now I have what I hope isn't a big one.

2004 C2, 125k miles. Lately I have had the power loss when it warms up on the highway. I've had it before and it's been the intercooler one time, and the pump another time. I thought this time was the intercooler, so I took it to MB for a checkup. They did the pressure test and pump test and told me it was the pump. Rather than pay them $1075 for the repair (seriously), I bought the pump from Needswings. I also had an old battery that wasn't starting in this Chicago weather, so I replaced it last week.

Today, it's 5 degrees and freezing cold. I go to move the car, start it up, and hear a loud clanking sound. After warmup, there's a rough idle, but no noise - until I put it in gear. Then it's noisy. Check engine light comes on, and I get the codes: P0300 and P0303. I understand the codes and will check the plugs/wires/etc., but I'm REALLY concerned about the sound when I put it in gear. It's not just a rough idle, but an engine noise.

Anyone have this problem before? Any ideas? Is the engine blown? I would love to only need new plugs and/or wires, but this one worries me.

Thanks for your thoughts!
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Old Feb 1, 2013 | 02:51 PM
  #2  
jayitx's Avatar
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Joined: Mar 2004
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From: Grapevine, Texas
2004 Capri Blue C32
Update......

Well, I talked to a couple of people, and tried resetting the computer. I disconnected the negative battery lead for about 25 minutes, plugged it in, and still had the problem. I plugged in my code reader to check the codes and had the same P0300 and P0303. While it was running, I felt it smooth out, so I tried putting it in gear. No more noise, no more rough engine. Skeptical, I cleared the codes, shut it off, and tried again. No more codes, no more rough idle, no more noise. Car runs fine now. WTF?!?!

Happy, but still skeptical.........
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