Powe drop

[Patrician]

Hello all

New to the forum and looking for advice / help.
I have a 1999 A6 Avant Quattro – 2.5 TDi (110Kw) and am having a little problem:
Occasionally the power drops away and the revs drop to 2,500rpm, it does eventually come back without having to restart. But it does not instil confidence!
Concerned it may be an electronic issue, though a fuel pressure problem could possibly give a similar problem ~ yet to be confirmed. . .

I have recently replaced the MAF sensor, air & fuel filters, etc. . .
But to no avail

Any & all advice welcome

[towcestervag]

get diag test done so it will give us a clue

[Patrician]

Booked into an Audi specialist in Burwell, not far from Cambridge.
Have had the power drop off again - twice
and at bad moments!

My confidence is some what shaken . . .

[MFGF]

Hi,

Do you get huge clouds of black smoke from the exhausts when the power drops? My 2005 A6 2.0TDi did this - the car would suddenly not rev past 2000rpm, had no power, and chugged out more smoke than a coal fired power station - then it would suddenly clear and drive as normal for a while. It was recovered by Audi Roadside Assist to a dealer in the South, but the dealer said no faults were registering. After having the ECU, MAF, fuel pump and fuel filter replaced and the tank removed and cleaned, the problem was eventually traced back to a broken EGR valve.

Obviously, mine was a different model A6 with a different diesel engine, so may be of no relevance in your case, but it may be worth checking to rule it out.

MF.

[Patrician]

alas no. . .
no big plumes of smoke!
Could betheEG valve, as you say - but it off to the audi specialst on Friday
:-(

Keep'm coming

[allan_audi]

Hello all

New to the forum and looking for advice / help.
I have a 1999 A6 Avant Quattro – 2.5 TDi (110Kw) and am having a little problem:
Occasionally the power drops away and the revs drop to 2,500rpm, it does eventually come back without having to restart. But it does not instil confidence!
Concerned it may be an electronic issue, though a fuel pressure problem could possibly give a similar problem ~ yet to be confirmed. . .

I have recently replaced the MAF sensor, air & fuel filters, etc. . .
But to no avail

Any & all advice welcome

I have seen an Audi Technical Bulletin for this, not sure if its the same problem..... Mines similar, I'm driving along normally suddenly the car loses all power, but usually recovers within a few minutes. If I check the diagnostic fault codes there is an intermittant high manifold pressure warning......

The bulletin basically is saying that the variable compressor veins in the turbo are sticking so its overboosting, then going into safe mode, advice is to check/lubricate all turbo linkages first, if persists, then to remove turbo and clean the inlet compressor veins.

[paul b]

There will probably be an overboost fault code.

Thoroughly check all boost and intercooler pipes first.

[Patrician]

Haven't had a look at the logs just yet - hopefully Monday.

I have turbo and cleaned the inlet compressor veins (NEEDED!!), also
lubricated all turbo linkages, etc. . .
Also cleaned EGR, new filter and new seals / gaskets.
But. . . .

I think he bearings are starting to go in the turbo, theres just a little movement and there shouldnt be!

[Patrician]

Ah hell - looks like the turbo is on the way out.
Probably got a few k left, but. . .

Melt down would not be good!!

anybody know where I can get a turbo from?
cost,etc. . .

[paul b]

I was lucky in the fact that for my Octavia (bought with a broken turbo) I found a brand new genuine one on eBay for just £280!

Check eBay for a genuine one in good, used condition or go to the dealers. You get a warranty of I think 12 months on the turbo whether the dealer fits it or you do it yourself.

From the dealers I'd prepare for a bill in the region of £800 for the turbo alone, nevermind fitting.

[Patrician]

:-(
Was quoted £650'ish. . .

These cars are the proverbial chocolat teapot!!!
Nearly as bad as Mercs

My old landy was so much more reliable!

Right, rant over! :-)

Anybody know the model & part numbers?
Or where I can find them???