A6 1.9 Tdi Lack Of Power

[senator]

Hi EveryOne!! I Have Only Joined Today & Never Used A Forum Before, I Need Your Expert Advise!!! I have Audi A6 1.9 TDI 2001 Y reg with 118000 miles which I purchased from a auction last week. Its a 1.9 TDi (red I, presume its a 115bhp??) Gearbox & clutch is excellent but engine is lacking serious power!!! Please help me.

Power is really bad when its cold, especially in morning...with accelerator pressed down all the way there is no high response...just toddles along, a Fiesta 1.4 is faster!!
Engine revs excellent when its standing, it doesnt restrict to certain rpm, revs like it should do
No smoke comes out from exhaust even when reved to red line, which is a good sign
When its reached its temp I get slight increase in power but not to what it suppose to be, I used to have a 1.9 TDI A6 2000 x reg before and that used to shift with 135k!!
I strongly believe it has lost around 70% of its power
Its absolutley rubbish on the motorway it struggles to reach 80mph and I am a regular motorway user due to my job thats why i am really worried!!! (seriously need your help)
I have unplugged the Air Flow Meter, took it for a spin but there is no power difference, no difference either when its plugged or unplugged:confused:
I have took the Air Flow Meter out, cleaned it & put it back in there is no difference
Cant see any oil leaks or loose pipes did check
Looks like its got a fresh Air filter
I can hear the Turbo whizzing fine, saying that engine sounds a bit deepI look forward to your responses and do exactly what you tell me to do before I take it to main dealer (if its not fixed) with a fat wallet:mad: already spent a fair bit!!

[Crasher]

Hello and welcome to the forum. First of all I recommend you fit an exchange genuine Audi AMM/AFM (I have had terrible problems with non genuine units) and these are quite affordable. Then have the fault codes read (there will be at least one code stored now you have disconnected the AFM/AMM, I keep telling people not to do this) and then drive the car again to see how it goes. If the performance is still flat have the ECU read for codes again and if any codes return, you will have a good idea of what to do.

[senator]

Ok, Thanks for that, I will try the dealers on monday and i hope it will cure the problem...reading through the threads I came to conclusion that if air flow meter is disconnected and there is no change the air flow meter is fine???!!! Also the engine management light is not on....

[Crasher]

I keep screaming about both disconnecting and cleaning the MAF, neither of these steps has ever helped me and cleaning the MAF usually kills them anyway and disconnecting it generates a fault code that could mislead and confuse a less experienced garage. The way I do this (with a flat TDI), is read the codes and if there aren’t any, change the MAF. A fault MAF hardly ever leaves a fault code or brings on the light on a TDI. It is a gamble but a reasonably safe one that has only caught me out a few times. Analysing the MAF’s output in Measuring Blocks 08 (using VAG-COM) takes as long that it can be cheaper to just fit a new one.

[senator]

Thanks crasher....i have changed my maf today and what a change!!! its back to normal..got the power back. amazing what a little sensor can do..once again thank you

[Padwick]

That sounds very similar to my Dad's A6 which is having problems at the moment.
It's got 140k on the clock (1.9TDi AJM engine) and it's just had its head skimmed, timing belt done, and water pump changed and hasn't been right since.
Absolutely no power at all until it hits around 2000 revs and still then it's not great. The car is still in the mechanics as it's still not going right, but I've told him to get the MAF changed if it hasn't been done already. Also isn't it true that you have to disconnect the battery for a while after changing the MAF to clear any present fault codes?

[Crasher]

First of all, are there any fault codes stored? If the head has been off and there is poor power delivery it is quite possible that the vacuum control system may be compromised due to a leak or incorrect connection of the piping, a fault code read will almost certainly be of help. No, disconnecting the battery will not clear the fault codes, the ECU’s memory is non volatile and an ECU that has been sitting on the shelf in a scrap yard for years will still have any fault codes it had logged before disconnection still in its memory.

[Padwick]

That was my original thought too. There was a similar problem with the car once before and it turned out to be one of the vaccuum hoses disconnected. Which was painful in the fact that the car got two new sensors (£180) before it was realised.

Thanks for that anyway. I've advised him to get the car towed somewhere to get scanned (too dangerous to drive pulling out at junctions, etc).

[Padwick]

No fault codes showed up on the car.
Mechanic reckons there's something wrong with the injection on it. I'm getting the info 2nd hand but he's talking about two-stage injection and there being a problem with one of the stages. Is that something to do with the tandem pump (I think the fuel pump is called) or how does the two-stage work?

[Crasher]

“No power, no codes, new Air Mass meter”-works in about 75% of cases BUT DO NOT fit a non genuine VAG AMM. I have a firm rule about only fitting genuine AMM’s as pattern unit’s cause so much trouble. Then I go and allow myself to be bullied into fitting a GSF supplied AMM today as the girl who owns the car is a skint student. Half an hour later I was pulling my hair out with the car running worse than ever, so I took the GSF supplied AMM off and fitted a genuine one. The car now runs perfectly and GSF will be getting the AMM back with a flea in the ear! That is three and a half hours in the space of the last week that GSF part have lost me due to them being cheap pattern ****! Effectively it means that cheap pattern parts have lost me nearly £200 this week alone.

[Padwick]

Good info thanks. I've told him to go that way with it.
Worth a try before ripping the head off again. I'll let you know how it fares out.

[Padwick]

Just a quick update on this.
Still no fault codes and a new VAG MAF fitted but no joy. He's since taken it off his mechanic as it was getting nowhere. Someone else he's got to take a look reckons the wastegate valve is not opening like it should when the car is started. It's just dead in the low revs and then knocks itself into safe mode when you hit high revs.

[Crasher]

If it is going into limp it must generate a fault code, he should do a requested and actual boosts pressures test in Measuring Block 08, Display Zone 11 Display Groups 3 and 4, do a logged run and then examine the results as a graph.