Hi guys- My '99 Honda Accord (auto, 4-cylinder, 173k+ miles) has been encountering a few problems ever since I recently bought it.
1) The car gets abnormally louder as it gets faster. At 25 mph, it's a slight hum. By 50 mph, it's an unbearable grinding sound!
2)The car is also very unresponsive- I need to push the gas pedal down very far to even accelerate at a reasonable rate.
3)The car also jerks every time it switches gear. HELP PLEASE!

On a side note:
-1 or more engine mounts are either broken/loose, which can be causing all 3 problems
-Transmission fluid is bad(its dark brown!)
-It's highly unlikely that the noise is coming from the engine/trans(proven- I shut off ignition with the car running at 40+ mph and noise was still present). My guess is that it's coming from the axle/bearing, but I couldn't be fully sure.
-As for transmission fluid, it is in need of changing(it's dark brown!). I'm thinking of getting a transmission fluid flush today. Please tell me if getting this flush would be worth it. Thanks mucho!

A flush could hurt your transmission. Just change the fluid and filter. Not sure about the other problem but it could be the catalytic converter is clogged. Do you have any check engine light?