Recently purchased a high mileage Insignia 160 cdti Elite with full service history in reasonably good condition considering the 102K miles on a 09 plate.

I have done approx. 4000 miles with no problems at all (motorway) but over the last few days I have noticed an intermitent problem. Traveling at approx. 80mph I get a big judder as if the car is labouring or going over rough terrain. This lasts for about 30 seconds and then it goes.

This morning was worse as it came and went for about two miles before finally returning to normal.

I have read a few things around dual mass fly wheel issues but considering it only happens when at speed with no clutch manipulation I am wondering (hoping) that its not this, given the repair cost!