2004 Honda Accord EX
4cy
Automatic

Had a slow vibration between 50-60 mph (kind of a whomping sound).
1)Recently had four new tires, allignment, but problem persisted.

2)Changed all three motor mounts with after market parts. Now, there is a new bad vibration inside the cabin at 900 rpm. Engine runs smooth.

3)Checked the front vacumm mount with no vacumm and full vacumm, but no change in vibration. Engine and Tranny are not touching anything to cause the problem.

Could it be the transmission torque converter? Or does anyone have any other suggestions? Would LOVE to hear any possible solutions. We have had 3 mechanics racking their brains over this issue.

 

#1 might be a wheel bearing?? At least check to rule them out.

#2 Not sure but I kinda remember there's a particular sequence of which mounts, & which bolts to tighten in which order. If you simply bolt em all up in random order the mounts end up sharing the load incorrectly.

When you checked the front engine mount (vacuum vs. not), was the transmission in gear with someone holding the brake pedal?

 

Vibration at certain speed is the axle if tires are balanced and alignment are ok.