Matt,

This may be worth a try:

http://www.powerenhancer.co.uk/product.php/839/archoil-ar6600-professional-diesel-turbo-cleaner

 

 

Do you know of anyone using this method? how have the results been?

 

I like this sort of method http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html however I dont feel confident enough to do it myself. and all the garages i've phoned up are asking for £300 (but they all want to take the turbo off and recondition it) which is a lot more work.

Mr muscle works but only short term, u can get innotec turbo cleaner as well but again unless u remove and split turbo it will never be properly cured, removing turbo and splitting is actually not to bad a job, hardest part prob the manifold bolts, the actual turbo is a piece of pee and straight away ur notice the crud inside,

Do you know of anyone using this method? how have the results been?

 

I like this sort of method http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/107121-un-sticking-your-tdi-vnt-turbo-vanes.html however I dont feel confident enough to do it myself. and all the garages i've phoned up are asking for £300 (but they all want to take the turbo off and recondition it) which is a lot more work.

I haven't used the AR6600 before but I have used the AR6400d product before at service and been happy with the results. I suggested the AR6600 might help you as it is targeted at turbo issues and one of the testimonials (the second one down) on the page I linked seems to mirror your exact issue and with a similar engine / turbo. There is more information on some of the causes of the issue you describe and the product on the following site:

http://www.oilem.com/turbo-cleaning-and-turbo-cleaners/

However, bear in mind the guy that wrote the info at the above link is the same guy who runs the site selling the products.

There are some 20% discount codes about for the site selling AR6600 if you do choose to try it.

I have not had much luck when using turbo cleaners that you simply pour into the tanks or spray into the manifold for that matter.  However the MrMuscle does seem to do the trick and is cheap, however I prefer the Innotec kit as it is a bit more comprehensive.

 

Try this 

 

http://www.ebay.co.uk/itm/Innotec-Diesel-Turbo-Cleaner-Kit-Solves-Your-LIMP-MODE-on-all-VNT-Turbochargers-/171235910545?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item27de74a391 

Anybody got a guide to cleaning the turbo exhaust side using one of these innotec kits or the mr muscle method for a octy MKII 140 TDI PD?

There's a simpler option to prove if that's the problem.

 

Move the VNT mechanism by hand (you should be able to get 1 or 2 fingers under the arm). 

 

It should move about 1" with minimal force.

 

If it's really hard to move or only has a tiny movement then your VNT is the problem.  Keep trying, it should eventually move, exercise it a bit until it moves a bit easier then go for a drive.  You should have 'normal' engine response again in all gears.

 

If the above works then you know that you need an invasive clean to fix it properly.