Audi A6 saloon 3.0tdi quattro 272hp

[Yuri]

Hi everyone. A bit of update on my a6.
Car went in for mechatronic,nox sensor,cylinder 5 glow plug and crankshaft position sensor replacement at Audi dealership last week Friday. I picked car up yesterday and been told that all is sorted. Car drives better,gear shifts much quicker and feels more powerfull. So i was happy untill i started car this morning to go to work and what do i see? Well lumpy idle for few seconds and emission control light on the dash.
I finished work and went to Audi to ask what the hell is going on with the car. They quickly plugged diagnostic and it came back with cylinder 5 glow plug. When i asked why didnt they change it they said that tech was thinking that glow plug fault ws because of nox sensor. Unbelieveble)))) Just couldnt belive it.
Also i complained about odd vibration when wheels are at full or almost full lock and starting to drive. They said that its because of wheel size plus the tyres are really good and grip really well. What a nonsense. After they did scan car i took technician.for a test run to show him vibration i complained about. Done it few times,well every time at near full lock at the begining of movement. Tech admited that indeed there is vibration coming from midle of the car.
All in i said that i would like to return the car,as its just no right and i dont trust this car no longer.
Will be waiting to hear from them now.
Really like the car,but too much problems with it.
Was it abused by previous owner? Why is it doing this?
Its very clean looking car. Matrix led headlights are amazing and trully are a state of art technology,but not reliable at this stage.

[bluezie]

It's a quattro, and they all do the vibration thing at full lock, especially on a hill, or if booting it. It's the Torsen centre diff-lock starting to lock up.
I've owned 3 quattros, and driven a few others, and every single one has done it. The only time they don't vibrate is a gentle pull away on reasonably flat ground, and the problem can be exacerbated by having very worn tyres on the front, and new on the rear, as this increases the differential speeds of the front and rear axles.

[A8Cruiser]

Agreed on the quattro vibration. All of my quattros have done this at various points. Only when turning out of a junction on a hill.

the tech should know this also. Check the trye depths etc.

[Yuri]

Hi. I read about that vibration. Mine does it even at idle,when in gear just let my foot off brake pedal and does it in reverse too. I know that its normal to some extent,but i think that in my car its bit too much. Tech was trying to say that this sound is not a diff but wheels are jumping. All tyres brand new bridgestones all 4 are same on 18 inch alloys.
Dont know if its true or not,but oil change in the front diff helps to sort this vibration. I know a guy back in Russia and his mate ownes VAG group independent garage and he says that when vubration.appears its time to change oil in the diff. Can confirm its true or false though.

What about statement that nox sensor could affect glow plug? Is that at all possible?

[Yuri]

Mine vibrates at any ground.

[bluezie]

What about statement that nox sensor could affect glow plug? Is that at all possible?

On the face of it it seems totally crazy! But you haven't posted the exact faults with the items. Do you have the full engine diagnostic scan, or even just the complete fault codes including their descriptive text? That may show why they came to that conclusion, eg if the codes were showing a wiring fault, they may have concluded it was a common to both items fault.
When a scan produces multiple sensor failures, 99.9% of the time it's not the sensors, but the common wiring, I did say in a previous post that something's not right to produce this number of failures at a very low mileage- but a broken or chafed common wire, or corroded plug easily could.

[bluezie]

BTW, a dead glow pug won't make the car start or run lumpy, or reduce its power. A TDI will start instantly without any glow plugs, unless the temperature is well bellow zero. Glow plugs these days are used to lower the warm up emissions, and are switched on for a long time after start up. There's something else going on here other than a dead glow plug, I'm leaning towards wiring.

[Yuri]

Well it runs lumpy first start of the day,but only for few seconds then back to normal. My bmw e61 530d has bad glow plugs and it behaves same from cold.
Fault code states cyl.5 glow plug activation. Emissions control light is on the dash too.

[bluezie]

Have you got the actual fault code/s, the above doesn't mean a lot.

[Yuri]

Will have it a bit later. Have vag com now so will scan it myself and see what codes i have. Will post on here so you knowledgeble guys could have a look at this and shed some light on it.