I finally got around to removing the EGR valve and cleaning it today, this is the first time it has been off in 176k miles so I was expecting it to be quite gunked up. It was fairly simple to remove; With both the engine cover removed and the plastic cover on the right hand side of the engine bay I then removed the 2 vacuum pipes and removed the clip off the intercooler hose and pulled this out of the EGR valve. Next I removed the 3 Allen bolts holding the EGR valve to the inlet manifold (the bottom one looks as though it is awkward to reach but proved to be fairly straight forward using an Allen key) and then removed the 2 x 12mm bolts holding the the pipe from the bottom of the EGR valve to the exhaust pipe. This is how the valve looked when removed:







It wasn't as bad as I expected considering the mileage! I decided not to remove the inlet manifold as it looked fairly clean with just a light coating of carbon inside.







Next came the messy part! I spent about 2 hours scrubbing and scraping the inside of the valve until it was spotless. It's best to wear latex gloves for this part - I used a metal scraper to remove all the old carbon. Once all the excess deposits were removed, I used an old toothbrush and a combination of Gunk engine cleaner and a carb cleaner aerosol spray to get the inside clean.







Then it was just a case of reassembling everything in the reverse order. I also replaced my coolant temp sensor with a new one prior to taking the EGR off. This wasn't as difficult as I expected it to be but would have been much easier had I taken the EGR off first. The plastic clip slides off towards the bottom of the car (I prised the clip out using a flat bladed screwdriver), the sensor then pulls out towards the drivers side inner wing (make sure the old o ring is removed) and then you quickly fit the new sensor complete with o ring before you lose too much coolant! It's just a bit fiddly as you can only really get one hand in due to where the sensor is located. Here's a picture and a video of where the sensor is located.



http://www.youtube.com/watch?v=_USGW04fQtw

I don't think there was much wrong with the old coolant temperature sensor - the only reason I changed it is because when the engine is up to full temperature the sensor is only reading 81C when you check the measuring blocks on Vag-Com. The new one only cost £12 for a genuine Febi sensor of Ebay so at least I know it is working correctly now.