I have a 2004 Neon SXT, 140,000 miles, that has a bad vibration (like driving over rumble bars) when in drive and under torque. This occurs when stopped holding the brake and while accelerating. In park or neutral it runs very smooth. The transmission shifts perfectly in all gears. I have already tried replacing the transmission fluid (very clean), new plugs, wires, ignition coil, 3 of the 4 motor mounts. No codes from cycling the key.

I am thinking torque converter, but was hoping someone could help properly diagnose it before jumping into that project. Is there anything else that could cause those symptoms? Thanks for any help you can provide.

 

Check your motor mounts and don't forget the side one in the fender on the passenger side.

 

Thanks for the quick reply. I replaced all but that one due to the difficulty of access. The transmission mount was just fine, so I didn't want to tear into it to find the same thing on the passenger side. If I don't get any other suggestions I will change out that last one when I get time and let you know.

 

When I did mine I believe I had the engine dropped down to get it out. Hope you find your problem

 

You called it! I replaced that last motor mount and it runs nice and quiet now. This is my daughter's car and she said she feels like she is driving a whole different car. Thanks for saving me a lot of time and money.

 

I am glad to hear it is solved !!😀😀😀😀