TDI Turbo faults

OK leaving aside EGRs, mooing and MAS/AFMs has anyone had experience with the variabe valve vane Garrett GT15 turbo charger?

My understanding is these units are prone to clogging up with exhaust carbon/particulates etc. This may cause N75 faults in VAG-COM and the lack of travel in teh vane actuators retrict the turbo boost so you end up with no power.

A very good site for pics on the subject is here:

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html

ecoangel said:

My understanding is these units are prone to clogging up with exhaust carbon/particulates etc. This may cause N75 faults in VAG-COM and the lack of travel in teh vane actuators retrict the turbo boost so you end up with no power.

Click to expand...

Yes, something like that can occur and has happened to the VTG-turbos of the 90 HP motor. Those seem to be less reliable than their wastegate- counterparts. Especially the VTG-leverage is prone to go stiff.

For examples please check out the links to the German forum here:

http://www.a2oc.net/forum/showthread.php?t=5986

Another nice explanation of turbo actuation here:

http://www.sgaf.de/viewtopic.php?t=31271

http://community.dieselschrauber.de/contenttopic.php?t=10810

http://community.dieselschrauber.de/contenttopic.php?t=2992



"translated"
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ecoangel said:

OK leaving aside EGRs, mooing and MAS/AFMs has anyone had experience with the variabe valve vane Garrett GT15 turbo charger?

My understanding is these units are prone to clogging up with exhaust carbon/particulates etc. This may cause N75 faults in VAG-COM and the lack of travel in teh vane actuators retrict the turbo boost so you end up with no power.

A very good site for pics on the subject is here:

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/vnt15-turbo.html

Click to expand...

Hey I was looking at this stuff yesterday! I've just bought some 10k diesel boost to clean me engine out. Anybody know where the best place to administer this into? Was going to do it after the maf.

Nice write-up and pics of the T15 turbo strip down.
For anyone else considering stripping their turbo I recommend you don't go any further than shown and dismantle the wheel and shaft assembly. These components are balanced individually then rebalanced as an assembly to extremely fine tolerances. Even if you carefully mark the position of each part, its unlikely the balance will be manitained after rebuilding.

Cheers Spike

I dont understand all that mumbo jumbo so in "SimpleTerms" whats the best way to avoid any Turbo problems please????.

andyman said:

I dont understand all that mumbo jumbo so in "SimpleTerms" whats the best way to avoid any Turbo problems please????.

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see http://www.a2oc.net/forum/showpost.php?p=46642&postcount=3



So for example

a) refueling at a motorway petrol station or
b) taking a rest at a motorway parking site

should be avoided - right after a full throttle drive.

Generally just give the engine/oil about 10 min to get warm (maybe 15 in winter time, non-eco aircon mode is beneficial) and a few minutes to let cool after a "heat." That's basically the essence to consider.

Agree with last in terms of turbo oil and keeping shaft from overheating.

However when it comes to soot and VTG / VNT then longer runs are actually much better or the turbo. It is stop start driving and low engine temps that create the most soot and this is also true of particulate filters fitted to newer audis becuase the CAT/PTF doers not heat up enough to remove the dirt it just gets trapped causing clogging.

New/Recon Turbo

After much research on German forums (Lupo 3L etc) it seems Variable Vane Turbos are going to cause quite a few headaches in the coming years.

A lot of modern diesel cars now have the Garrett VTG/VNT system and if used for short journies wherer turbo temps are not so high, soot becomes a major factor.

My dad's Peugeot 307 HDI 1.6 had the same issue and failed in just 50k / 3 years.

Just bought a new/recon unit from turboactive - just north of middlesborough.

£270+VAT plus exchange unit - they do a delivery and pickup service for £8+VAT where you get new turbo for up to 2 weeks before they pick up exchange unit.

Audi UK quoted £616+VAT for re-con exchange - and guess what? It's not even in stock!

Given time and tools probably could have cleaned old one and re-fitted.