I have been trying to find a 1800 + vibration in my Mustang since I bought it last year. At first I thought it was the wrong weight size on the flex and harmonic balancers, that wasn't it. It made it worse. So I put the 28oz weights back on and had a idea...............

Looking at the exhaust, custom welded when they did it. The mounts that they had used to hang it. Did not allow any movement in it at all ! So it was being transferred to the body. I cut their metal connectors in half, heated and bent them. Then installed some rubber separators to allow the exhaust to actually move. Low and behold the vibration is GONE ! It has never been so quite in the car ! ! !

 

Beautiful.

 

Now to just figure out the bucking at idle when in gear, and the turn signal clicking all the time. Noticed last night when I drove it that the shifter light flashes in sync with the flasher clicking. Not a full click, but a light click...

Will check the wiring and grounds, and the timing on the engine. I did notice that the pcv grommet is not a tight fit anymore. So I have one coming from CJ Pony Parts..