Jacko2479

Hi, I have a 2007 A4 2.0 TDI. I also have a flashing glow plug/coil light, and the car goes into semi-limp mode. When I say semi I mean the car will still drive at 60mph, but there is no turbo so sluggish. It's been in the garage for new glow plugs, electrical wiring inspected and new vacuum valve but the issue is still there. Any suggestion would be appreciated.