Skoda Octavia gas recirculation valve problems - what's the cause?

About 18 months ago I had my Skoda Octavia (2012 model) 1.9 diesel valeted. The firm that did the work also washed the engine, even though I never asked for the work to be done. After this the car experienced lots of fault lights – glow plugs, turbo, engine management. My local garage checked and reset the on-board computer, but the warning lights continued to come on until the summer. Now, with the damp and cold winter, the warning lights are back. I have also been told that the turbo and gas recirculation valves need replacing. Can I get these parts tested after replacement to find out what went wrong and why? The car has done 95,000 miles and is regularly serviced every 10,000. I always use Shell “best” diesel.
An EGR's life is only 80k - 100k miles anyway. The most common reason for turbo failure is blocking of the turbo bearing oil deed and oil return pipes with carbon, from switching the engine off when the turbo is too hot. These pipes also need to be replaced.
Answered by Honest John on

Ask Honest John