I got an oil change from the dealership last night and now my car sounds funny. It sounds really loud, like I'm missing the midpipe or something, except that it's coming from the front half of the car (front seats and forward). I looked under the car when I got to work and everything underneath appears to be there (given how well I can see under the car with a 6" clearance and all) Is this normal?? Could the engine just appear to be louder b/c the oil is clean? I mean it's LOUD. Start-up is very noticable, and then around 4k RPMs it "opens up" and is louder and clearer, and becomes more subtle again after 4500k or so.

Any ideas?

 

Did they do anything else besides the oil and filter change? Did you check the oil level? That should be your first step in case they forgot to put in the new oil. Make sure they reinstalled the cap on the oil filler tube. Take a flashlight and look around the oil filter for telltale signs of a problem. Also look around in the engine compartment for tools or debris that the tech may have left in there.

New oil should not noticably change the engine sound. I would suggest that you not drive the car much until you determine the source of the noise. Return the car to the dealership if you can't find the source.