New manifold, new sound

After having a new intake manifold installed due to the old faulty one that buick put in. my car sounds different. It had gotten a "mush mouth" moan when i would get on the pedal. now it has a crisp clear " lobe" or " loam" as different people call it. was the bad manifold allowing coolant into my engine and stealing power to cause this sound difference?

any ideas>?