2006 Audi A8 D3 3.0tdi 'Sudden Power Loss'

[meffe]

Hi guys, Im hoping someone here can help. Driving along through town the other day and noticed the glow plug light flashing continuously. When I tried to power or downshift in gears, it was in limp mode and struggling to get to 40mph. Turned car off and restarted and all was well for a few minutes then it did it again. Left the car on drive over weekend and tried again this morning and noticed the engine management light is on constantly and the glow plug light is no longer flashing. I've now taken to a friends garage and a quick vagcom diagnosis came up with the 2 following errors: 13128 (P3348) - Activation, turbocharger1 control unit - J724 & Error code 6256 (P1870) - Gearbox mounting valve. I've been advised the problem is turbo related to the power loss and possible replacement. Ive checked online and had a few different conflicting reasons from a 'cleanout' of the turbo unit to a replacement for a new. I'm not a mechanic or very technical minded, so all help is appreciated. Ive checked on places like ebay and new ones are around a bag of sand, whereas a used are around 4-500 quid? any ideas? Im based in Manchester, so if anyone can point me in the right direction - that would be brill!!

[EG-4.0TDI]

Might be worth getting the control linkage lubricated and freed up before condemning the turbo. Sometimes the link rod from the actuator to the vanes ceases up which throws a flashing glow plug light because the actuator can't achieve its full range of motion.

A little bit of a long shot, but for the sake of about 20 mins might be worth a go!

[somerandomguy]

I had a similar fault, which consisted of the electrical fault code you have , followed by an under pressure fault if i kept my foot down when i felt the loss of power.
For me, the issue was a split in the hose connecting one of the intercoolers, following an accident. I think that the turbo does dynamically learn the parameters as i was running around with the air leak for a couple of weeks and getting the fault whenever i put my foot down especially when loaded with passengers, or going up hills. For about another 2 weeks after fixing the leak the errors gradually reduced in frequency, but still popped up about once a month, compared to at least every day.
i then found a second leak 6 months later, which pre dated me owning the car by about 50,000 miles according to my trusty master tech. Even after fixing this, it still threw a fault when i was pushing 130mph on the autobahn a few months later, but havent had it appear for another few months.

After each time fixing, the fault codes were the electrical one as before, but followed by an overboost code

During diagnosis I tried running turbo cleaner in the fuel, lube-ing the actuator linkage.

I think that the turbo re-learns the pressure vs position so any changes to the air pressure system throw this out of kilter and at extremes it either over or under boosts, and it needs to be reset. Pushing the car seems to do this, but obviously the higher speeds and prssures are hard to achieve legally!

I did look at replacement turbo, as the variable vanes are notorious for wearing and sticking, but am waiting to see if this problem is sorted. Buying from gmany appeared to be the most cost effective source, but according to some, the turbo replacement process requires a one time adaption, And i am not sure if the refurbs/second hand ones can do this.

[meffe]

Hi Guys,

Just a quick update to say thanks for your help in this matter. I took the car to a specialist in Stockpot - AUDI Doctor. He was the 3rd person to diagnose the fault to the Actuator itself, however, this guy knows what he's talking about as he gave me a full breakdown explanation of the problem, and also said the part was available to replace. Happy to say, the new actuator has now been fitted, and the car is all okay now - no flashing coil light/no engine light - faults gone, and the car has its power back!

Thank you once again for the support..

Saf

[vwpassat]

Hi all. I'm having the same problem with my audi a8 3.0 tdi facelift. The glow light comes on then it goes in limp mode. After a while driving in limp the engine management came on. I don't have vag. So I used torque software on phone which gives a generic code. ImageUploadedByTapatalk1371464867.161876.jpg

any ideas appreciated. I'm from Shipley in West Yorkshire. If anybody knows of a trusted audi specialist then please let me know. This is my first audi. Thanks

[meffe]

Hi Mate,

I got the problem sorted with 'the audi doctor' in Stockport.

This guy (james) came highly recommended. I previously owned a few BM's and used a specialist in stockport. The guys here knew all there was to know about BM's. So i contacted them with my problem and they put me onto the Audi Doctor. The diagnosis did come back the same as the previous 2 garages i checked with. However, The difference was James carried out a full inspection and came up with the 'actual faulty part' - actuator.

Try him and see..?

Audi Doctor - Hope Street Garage based in Stockport, Specialising in Audi,VW Seat,and Skoda - Service, Repair and Diagnostics.

[vwpassat]

Thank you for your help

Just hoping there is somebody closer to bradford/leeds side as stockport is about 50 mile drive.