HELP - A4 2.0 Tdi Engine Problems

[A4NA18]

Hi All,

I will try to be really short...

I have a 54 Reg A4 2.0Tdi 140 (B7), 96K miles.

Symptoms:
1- No power at low RPM (nothing until 1900 rpm), nowhere near what a 140 should be like
2- loads of black smoke (I mean LOADS) under hard acceleration; not so much when accelerating slowly
3- idling at 950rpm, is it normal?
4- when stationary, along with the usual diesel noise, there is a non regular tapping noise coming from around the alternator; any idea?
5- Combined MPG is....34MPG....

Recent VAG com check showed:
1- EGR overboost
2- 2x glowplug issue

The garage doesn't know what to do (has been 6 month that they do not know...)

I thought about a sticky vane turbo situation and looked at Innotec but I did not want to go ahead without second opinion.


Any idea?

Thx for your help guys.

 

[A4NA18]

No idea anyone?...

 

[Fahim]

If your car was going into limp mode, i would have suggested the Innotec Turbo cleaner like you suggested, however because you have a EGR problem and glow plug issues i wouldn't bother with that.

Your glowplugs could be shot, and so smoking a lot under heavy acceleration. The glowplugs stay on, and do not turn off within the first few minutes of starting a diesel in cold weather so if yours arent working, the fuel won't be burning correctly in the cold and thus heavy smoke.

So the question is, does yours smoke a lot constantly? even after the engine is fully warmed up?

I'd pop into Awesome GTI and have the boys have a look. They are excellent and not as expensive as you may think.

Cant help with the EGR fault. Perhaps you should give it a clean out?

 

[A4NA18]

Hi Fahim,

Thanks for your input.
The black smoke is constant all through, even if the temp goes 90C and it always happen under hard acceleration.

Either way, it is so sluggish that glowplugs only cannot explain it imo.

The black smoke is quite bad so I suspect a clogged up EGR valve, and turbo maybe...

IT does go to Limp occasionally after hard acceleration though.

Thanks for your help.

K.

 

[A4NA18]

Ok, Full service booked with Awesome GTI, explained the issues.... Keeping posting when I have more news...

 

[Fahim]

Good to hear, let us know the outcome. I'd be interested in what the problem was!

 

[A4NA18]

Hi there!

Ok so go the car back from Awesome... but it is not fixed yet as it was on a saturday.

Anyway, I got the following codes:

01543 - Parking Aid Warning Chime (H15)
006 - Short to Plus

01547 - Sensor for Parking aid; rear Mid-Right
004 - No signal communication - intermittent

17055 - Cylinder Glow Plug Circuit (Q10): Electrical fault
P0671-000

17057 - Cylinder Glow Plug Circuit (Q12): Electrical fault
P0673-000

17058 - Cylinder Glow Plug Circuit (Q13): Electrical fault
P0674-000

16618 - Boost Pressure Regulation: Limit Exceeded (Overboost Condition)
P0234 - 000

16485 - MAF Sensor (G70): Implausible Signal
P0101 - 000

Right now, the CEL light came back on yesterday.

Black somke is still full on under hard acceleration and it is still sluggish. After the full service the MPG got better so this is the good thing at the mo.


So it seems basically that I have to replace 4 glow plugs and check the parking sensor circuit, and finally tackle this Overboost and MAF condition.

Any idea?

I was looking at the engine bay and I could not locate the glow plugs: where are they? Also which glow plugs should I buy? is it something I can do on my own or is it another trip to the garage....?

Cheers for your help!

 

[A4NA18]

anyone?

 

[gphilla]

I have recently changed my glow plugs and it was a bit of a **** of a job as they are under the rocker cover deep down inside - it is do-able but be patient and give yourself an hour or so

 

[Kaysvay]

Hi,

I have a A4 B7 2.0 TDI 103kw BLB engine with 268k km on the clock. I had 3 out of your 5 Symptoms:
1- No power at low RPM (nothing until 1900 rpm), nowhere near what a 140 should be like
2- loads of black smoke (I mean LOADS) under hard acceleration; not so much when accelerating slowly
3- idling at 950rpm, is it normal?

I tried all these with no luck:
Injector Cleaner, turbo VNT cleaning, decat, cleaned motor intake flap and drained all the diesel from the tank

In my case, It turned out being a faulty EGR - it was stuck in the open position. blocked it off at the cooler and at the motor flap@intake manifold sections and its running perfectly for over a year with NO error codes.



I just used 1mm piece of steel to block it off.

Hope it helps

 

[A4NA18]

Kaysvay,


I have the same symptoms but could I ask you how exactly you did it as I would like to do the same. Did it affect the MPG?

Cheers.

 

[Kaysvay]

Kaysvay,


I have the same symptoms but could I ask you how exactly you did it as I would like to do the same. Did it affect the MPG?

Cheers.

MPG - my daily commute changed from highway to city driving so I cant really compare them. Current Avg is 7.0l/100km

I added the steel plates in the red highlighted areas:

The brown "thing" is a paper gasket that I added afterwards. its optional.
If it is the EGR thats stuck open, then I suggest you clean the intake manifold (and replace gasket) because of all the exhaust soot.

Good Luck!

 

[OttoDiesel]

Black smoke is an indication of overfueling

Black smoke and low power is an indication that the turbo is shot.

It's posible that the sensors in the system are malfunctioning and overfueling the engine.

If you don't let a turbo engine idle for a couple of minutes before turning it off, you will prematurely destroy the bearings in the turbo.
This is caused by no oil being pumped to a bearing that is still spinning at high rpm. So if this sounds like you, you probably have a bad turbo. If it grenades, you've got a blown engine.