Audi Pull Back/Surge/Shudder after 120kph

[Audi Power-SA]

I am a new member from the beautiful South Africa, and firstly would like to say Hi to everyone...


I have an Audi Q5 3.0TDI and have been having a problem when driving 120kph and above, especially on uphills, where the car would give a pull back/surge/Shudder every now and again...Sorry this is the best I could explain the problem...I tried changing it to manual but still get the same problem. Audi have had my car for over 6 months, they have changed the gearbox, engine mountings, tyres, oil, oil filter, fuel filter, ecu mappings changes, changed diesel suppliers, used diesel 50ppm & 10ppm, used diesel cleaners, no faults reported on the system even when driving with the laptop plugged in and the problem surfaces...Is there anyone that has had similar problems, or can guide me on what the problem could be as it looks as though Audi is running out of ideas on what the problem could be?

Thanx.

[shabazmo]

Sorry, I can't help but try posting on this web site. its more active forum. myAUDIQ5 forum (http://www.myaudiq5.com/index.php)?

[Audi Power-SA]

Sorry, I can't help but try posting on this web site. its more active forum. myAUDIQ5 forum (http://www.myaudiq5.com/index.php)?

Thanx, I have also posted it there, tried a few of the Audi forums in order to get guys from all over to assist ;)

[aldfort]

Sounds like its more mechanical to me. Probably why there is no fault code. Could be lots of things looking at your description - do you experience an apparently momentary loss of power followed by what feels like a momentary power surge?

[Audi Power-SA]

Sounds like its more mechanical to me. Probably why there is no fault code. Could be lots of things looking at your description - do you experience an apparently momentary loss of power followed by what feels like a momentary power surge?

To me it feels like the car is struggling to get power...Something like a misfire for petrol cars...

[aldfort]

To me it feels like the car is struggling to get power...Something like a misfire for petrol cars...

it sounds like it may either be the turbo or something is causing partial fuel starvation. Although both of those things should generate a fault code. One thing I would check is if the problem is better or worse full fuel tank or empty fuel tank. It's a long shot but if the fuel system is pulling in air it might cause this type of issue. Given the fuel is highly compressed any entrained air is hardy noticeable until the exact moment of injection. - Best of luck.

[niall campbell]

Loss of power, maybe mass air flow meter problem or blocked air filter.

My mate just spent £1,000 on new turbo & cat on a nissan car & said it wasnt quite right with a flat spot.

Took off the air filter and never seen such a choked filter bar on a tractor.

The dust was unbelievable. The garage thought the cat was choked due to oil leak in turbo, when the engine was running rich in diesel due to no air.

Not saying this is whats wrong, but simple basic checks can help.