Audi A6 2.0 tdi Auto Engine Vibration etc

[imastu pidgit]

Just developed a fault today - symptoms are:

- a vibration, almost a shaking, of the engine (bonnet open) when stationary;
- the vibration comes through the pedals and the steering wheel;
- worst at low speeds and setting off;
- a tapping sound from the bonnet when driving at all speeds;
- it feels like the level of vibration reduces after a while, but that could be wishful thinking;
- no loss of power;
- no warning lights;

Having trawled the forum and google, it sounds like it could be anything from the dual mass flywheel, the entire engine, the timing belt (which I have just had replaced).

Before the obligatory trip to get fleeced, does anyone have any suggestions of what the problem is?

[a8 tech]

You do not have a dmf, check mvb group 04 zone 4 to check the timing has been correctly set in address 01 value should be -2.5 to +2.5

Drain the fuel filter and check for excess soot content in the fuel

check fuel quantity at idle mvb 01 group 02, range 4.5mg/h to 9mg/h

run basic setting of egr channel 03

EGR active and EGR inactive should differ by
at least 120 mg/stroke

Check for excess black smoke, possible tapping caused by exhaust gas leak at the egr cooler pipe or hairline split at the inter cooler (whooshing noise)

Also the egr valve port flap breaks away from the spindle

Other tapping related noises caused by air con compressor pulley failure.

The information given allows you establish uneven idle causes and I would question the possible link to the cambelt change, I see lots of issues with the valve timing due to incorrectly aligned pulleys or incorrectly tensioned cambelts

[imastu pidgit]

Because it's an automatic? Ah, my technical knowledge...

Thanks for the quick response - I will admit to not knowing much about the other first few suggestions either, and will probably have to take it to my local independent (Fontain) for a fix. Just odd that it suddenly came from nothing - had just driven about a mile, I stopped and switched off, started it again a few minutes later and it happened suddenly while pulling away.

But to the extent that I now know it's not necessarily going to be the horrible expense of a DMF replacement, I'm comforted...

[a8 tech]

There is a type of dmf fitted to the multitronic but its only real fault is harsh noise from cranking

I suggest you seek a dealer as there are so many threads that start with

been to local garage, fitted x,y,z then took it to dealer after they couldn't fix !!!!!!!!!!!!!!!

Dealer found x, y and z not required but needs !!!!!!!!!!!

Save yourself the hassle and expense, Audi dealers are after all are supported by the manufacturer

Good luck

[imastu pidgit]

Many thanks - to be fair to them they are an Audi specialist, albeit independent. And I've not always read flattering things about Audi main dealers on here, in terms of both technical expertise and price.

I'll post how I get on, assuming I still have a home to live in after the bill...

[imastu pidgit]

This has just got very serious - I am being told a piece of one of the pistons has broken off and the bore has been scored. Upshot is a new engine.

Does anyone have an idea how much we're talking - 2.0 tdi, either new or remanufactured, or used?

Edit -see quotes on ebay and elsewhere for £1,200 to £1,600 fitted, with all sorts of caveats. Add in the full cost of putting the car back together, profit margins to the repairer etc, would I see anything left from £4k?

[imastu pidgit]

Only just got this back yesterday - I'm sure if anyone from the dealer is reading this, they work can out who I am...

All-in cost for investigation labour, replacement engine incl labour and a new egr valve was £5,250.

On the bright side, at least I got something for the money (a new engine) rather than a couple of thousand spent on labour costs and not finding much, or not actually replacing much.

But the one big lesson is to get a warranty if you can - I have had big german estate cars bought when 3-4 years old and have lost initial depreciation for around 10 years now (this is the third), but never had anything like this, therefore never considered the particular need for a warranty. I think maybe for a small cheap car, not so necessary, but for something like this, it's too big a risk.

Needless to say, am now committed to the car for a number of years to get back some sort of return on the investment...

[nevbadger99]

Scary. How old is your car?

[imastu pidgit]

May 2008 - so less than 3 years (more like 2 and a half when it happened). But it had done 90k miles, hence no manufacturer's warranty.

Had I known at the start that it would need a new engine, I might have gone to a dealer and tried arguing the case for a contribution - but for what felt like an unpleasant vibration and no more, I didn't expect it to need a replacement engine...

[nevbadger99]

Yikes. I had a Mini that did that once, except because the gearbox was underneath the engine the rogue bit trashed the gearbox as well.

Is it worth a letter to Audi to see if they will contribute anything?