Hi. I have a problem on my octavia Vrs 2008 170 tdi. I was driving quick down the motorway and coil light started flashing. When I slowed down to traffic lights. I had no boost taking off until 3k revs. I got home and next day started car. No coil light on but still no boost again til 3k revs. I'v had a diagnostic test done but nothing is showing. Tried several times. It's had fuel lines cleaned but still has no boost. Whenever I give the car some stick the coil light starts flashing. Also the exhaust sounds blown which isn't normal. Has anyone came across this problem?? Please any help appreciated. Thanks.

I would suggest that you have a good look at the system for boost pressure leaks for starters.  After that I would be looking to make sure the turbo vane actuator is not sticky.  Could also do with getting the fault codes read by VCDS.  Have a look on the owners map.

I had a similar problem that turned out to be the diaphragm in this vac unit thing (pic from a seat but similar thing)

 

 

Part number for mine was 03G 129 061 A 

The part itself was only around £20 but the problem was getting to it as you have to take off the anti shudder valve, EGR valve and the intake manifold to get to it.

It's not massively difficult but its a bit of an arse. 

Basically it controls the flaps inside the manifold, so if the diaphragm's gone, the flaps don't move. If you do it yourself don't forget to replace all the gaskets/seal for the EGR and manifold as well

Edited 14 September, 201510 yr by cavaian

Apparently it's the actuator. So new turbo unit says the mechanic??

Nope, apparently you can get the actuator separate, darkside developments are the ones to visit so im informed..