Vibration Above 40mph Stops When Braking or Accelerating

[Michaellong]

I haven't had a chance to lift the other wheel and try shaking it as it was getting late, but I did notice that the shaking only happens between 40-60 mph and goes away if I go slower than 40 mph, faster than 60 mph, am braking, accelerating, or have my foot on the gas. It is the worst between 40-50 mph. The car does not pull to one side at all. The previous owner had a mechanic look at it when the car was misfiring, and the mechanic said that the car needs a new engine mount. Could that cause this issue? I think a bad engine mount would only cause clunking when going over bumps or hitting the gas and letting it go. The car does not clunk when hitting the gas or going over bumps. It does make a rattling noise from the camshaft chain tensioner though.

[Davdraco1]

It's a possibility. It could be that the engine rpm is just so that the frequency of it is causing the engine mount enough stress that it's not working properly. Look up bedrooms of cars with bad engine mounts. Most you see are sever causes but you'll get the gist