Doesit do it if your drive with very light throttle- as you would if you did not want the turbo to come in? If so, could be sticky linkage on turbo wastegate, or fuel and filter related perhaps. There are no glowplugs, no EGR to cause similar on the JTD. But I think there is something that detects temperature, some other cold start device that involves external burn of fuel IIRC? Maybe that? I'm told these start reliably in really low temps without this device kicking in, read some thing on here and in the eLearn.
Might also be a badly worn, poorly lubed CV joint, or a failing engine mount causing a simlar feel.
