I have recently bought my self an 07 plate A4 sline 170bhp quattro,2L TDI, high 80's for mileage. My problem is several times over the weekend car would go into limp mode with the glow plug light flashing at me it will go away when I turn the ignition off then on again. I am pretty sure it comes on when for example I am in fifth or sixth cruising 60-70 and when the road goes into a kind of long drag that makes you press the throttle down a bit more and put the engine under a bit more load. This happened on Friday twice and 3 or 4 times today between that over the weekend nothing, and I was doing a wee bit of running around and on occasion I would give it a fairly aggressive acceleration/thrashing with no hint of the a fore mentioned problem. Obviously my intention is to speak to the people that sold it to me but they for me are a few hours drive away so I am just looking for a bit of advice/knowledge for when I do speak to them to find the best solution.