I just got a ‘98 Neon H, automatic, SOHC 134k miles. I’s been sitting idle for a year. I changed the valve cover gasket, vacuum lines, oil, filter, and spark plugs. I also re-soldered the instrument cluster due to speedo issues. I am getting a thud from the front end when accelerating quickly from stop. It doesn’t happen with slow acceleration. Any ideas?

 

Unless you're hitting something, it sounds like your engine mounts. There are to on the passenger side and a transmission mount on the drivers side. The upper comes apart and part of it is a bear to get to. The lower is easy to replace. The transmission mount is not easy, but not too bad.

 

Thanks, I’ll look