Moved your thread to the Older Rabbit Forum where you will get answers usually faster.
When mine did the Vibration it was usually the passenger side motor mount was shot.
But if your timing wasn't spot on, as with use of a Dial Gauge, then your engine wouldn't run as smooth as it can.
Worn shock mounts can cause the vibration as well, and there are thread here and on the VW vortex that tell you how to get a little better mileage out of them.
Check your rear tranny mount, as they can and will go bad quickly as well as the Front grill mount, if it isn't centered it can cause a bit of an idle.
As you didn't say if this was on a colder engine rather than a warm one, that is a possibility, and you said it was a idling issue as if you have some burned out glow plugs that can cause a cold to warm idle issue and vibrations from hades.... but the caveat is that you have to remove them to really see if they are bad, and the number 1 and 2 usually require that you remove the fuel lines to get to those....
Damper on the fan? I do know that the early westys has a negative air displacement issue on the Radiator mounts Bolts at the bottom, and a clip on the top that can lead to ripping the seam of the radiator tanks. But that can be reduced by the installation of the Cabriolet Pin Radiator and the Cabriolet radiator mounts that at the top bolt the fan shroud to the valance. I have a how do I do that on trimming the radiator shroud to make it easier on and off....
First suspect is worn mounts and if you didn't use the HD Diesel ones then the Gassers are more prone to vibrate, and some sellers sell the gasser ones for the diesel.
Second is cold or war? So I would look at GP's all working.
Third is Idle or the injection pump timing with a dial gauge.
When mine did the Vibration it was usually the passenger side motor mount was shot.
But if your timing wasn't spot on, as with use of a Dial Gauge, then your engine wouldn't run as smooth as it can.
Worn shock mounts can cause the vibration as well, and there are thread here and on the VW vortex that tell you how to get a little better mileage out of them.
Check your rear tranny mount, as they can and will go bad quickly as well as the Front grill mount, if it isn't centered it can cause a bit of an idle.
As you didn't say if this was on a colder engine rather than a warm one, that is a possibility, and you said it was a idling issue as if you have some burned out glow plugs that can cause a cold to warm idle issue and vibrations from hades.... but the caveat is that you have to remove them to really see if they are bad, and the number 1 and 2 usually require that you remove the fuel lines to get to those....
Damper on the fan? I do know that the early westys has a negative air displacement issue on the Radiator mounts Bolts at the bottom, and a clip on the top that can lead to ripping the seam of the radiator tanks. But that can be reduced by the installation of the Cabriolet Pin Radiator and the Cabriolet radiator mounts that at the top bolt the fan shroud to the valance. I have a how do I do that on trimming the radiator shroud to make it easier on and off....
First suspect is worn mounts and if you didn't use the HD Diesel ones then the Gassers are more prone to vibrate, and some sellers sell the gasser ones for the diesel.
Second is cold or war? So I would look at GP's all working.
Third is Idle or the injection pump timing with a dial gauge.