I'm getting vibration from my belt tensioner assembly especially at cold idle. You might check the lower end of the tensioner pivot arm where the damper shock attaches and see if it is causing your vibration.

Could be a weak glow plug at start up with compression creating sufficient heat at operating temp to even idle out?

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)