New owner, rough idle, black smoke, hesitation - help/ideas needed please!

[margin-walker]

Hi everyone, I'm hoping to call on your collective experience and expertise. I'm 4 weeks into owning a 2007 A4 TDI 170 s-line quattro special edition. Great car, big improvement on my previous A3 but from day one I've experienced a problem that has yet to be solved.

Symptoms

• Rough/lumpy idle (intermittent), jumps between 900 and 1000 rpm
• Engine shakes when idle is rough
• Black smoke (excessive) - both on idle and under acceleration, chokes cyclists who get overtaken
• Hesitation/flat spots - particularly in 3rd gear, at low revs, but car pulls well at high revs to the red line
• All appear when engine cold or hot
• No warning lights show (like DPF, check engine)
• No error codes

Fixes/inspections so far

• Audi garage ran diagnostics, no error codes, say nothing wrong with car on a test-drive, confirmed injectors had been replaced under the recall 18 months ago, weren't interested in problems
• Independent garage run full diagnostics, no error codes, but thought it may be egr cooler. Ran overnight pressure test, said engine/injectors were fine but cleaned manifold out, said it needed a 'good run down the motorway for a few hundred miles (the dealer I bought it from arranged all of this and weren't tech-minded so I'm not sure what 'manifold' he cleaned but he spent a day looking over it, told them if the problem persisted he could do a 'de-coke')
• I dumped a can of BG244 into a full tank of V-Power to see if it would make any improvement (mpg seems to be better)

. . . but the symptoms are still there. The dealer I bought it from did go out of their way to help, taking it to Audi and, not satisfied with their explanation, taking it to another independent specialist because they could see the symptoms and thought it wasn't quite right. However, all say there's nothing wrong with the car but I refuse to believe it as extensive google searches bring back lots of cases of similar symptoms but few solutions. The dealer I bought it from were really helpful if severely lacking in mechanical knowledge so wouldn't question any hypothesis thrown at them by a mechanic and aren't very local to me so I'd prefer to arrange any further investigations myself.

Any ideas, anybody?!

The other thing I've seen is a few companies doing re-map, DPF delete and EGR delete specifically on the TDI 170. Has anybody had this done and is it a potential solution?

Thanks in anticipation.

 

[NHN]

Boost leak as black smoke is poor combustion.

 

[margin-walker]

Thanks NHN. I guess that could be a simple fix, tricky to find, and something so basic any garage should have considered?! Audi’s attitude of ‘no error codes = nothing wrong’ has been a big disappointment.

The other thing I’ve noticed, on changing gear it sounds like it’s got a dump valve, venting to atmosphere, is this normal for this engine? I can hear the turbo spool/whistle but my other car was an impreza so I’m used to all of the whistles/whooshes/pops that made but don’t know what is abnormal for the TDI 170 engine.

 

[markyp2002]

Sounds like your recirculating diverter valve is faulty to me (forgive me if im talking rubbish here, im sure this is the case). I had a similar issues on an old 1.8T Audi A3, changed the diverter valve and that fixed the atmospheric sound, never had any error messages or anything and it didn't seem to effect performance too much in either case!

 

[MyMateDaveDJ]

Im in a similar situation with an A3 iv just brought, same year and engine i believe.
Idle issues, clear smoke, hesitation and DPF error codes.
Hope you get it resolved!

 

[Molnboman]

Engine shaking at idle?....sounds like your dual mass flywheel may be going "bye bye" too. Does your car vibrate heavily in first and second gear? Tell tale signs that your Flywheel is f@cked Matey. Is there any noise difference when you press the clutch in, when in gear?

BR
A

 

[d4dubs]

Coil pack?

 

[NHN]

Coil pack?

Its a TDI.

 

[margin-walker]

Engine shaking at idle?....sounds like your dual mass flywheel may be going "bye bye" too. Does your car vibrate heavily in first and second gear? Tell tale signs that your Flywheel is f@cked Matey. Is there any noise difference when you press the clutch in, when in gear?

BR
A

Hi Molnboman, thanks for your input! There's no vibration/shake when accelerating, it just happens on idle, but it's intermittent. When the idle is steady at just above 900rpm the engine is also steady, no shake, but when the idle decides to jump up and down by 200-500 rpm it's accompanied by the engine shuddering. The engine switches off fine, ie: no shudder.

The car accelerates well and pulls to the redline, but it has occasional flat spots/hesitation at lower revs, under 3,000 rpm. Somebody has suggested that perhaps the EGR valve isn't closing fully. I'm going to try and get my head under the bonnet when the rain stops and stand there scratching my chin in anticipation of a light-bulb moment.

 

[margin-walker]

Okay, so I took the top engine cover off and had a good look around, tugging/squeezing the hoses, all connections are tight and I can't see any obvious splits/holes in any of them. The only thing I noticed was the plastic air intake which feeds into the airbox wasn't properly sealed where it joins in the middle. See photo, I've outlined in red where it needed pushing together to get a better fit. I'm guessing this won't have much affect.


I ran the engine for 10 minutes and revved it a few times but couldn't see/hear anything unusual. BUT, when I switched the engine off I could hear what sounded like some servos working away and a slight hissing noise, like air was being expelled for about 6 seconds. Is this usual after switching the engine off?

 

[margin-walker]

Im in a similar situation with an A3 iv just brought, same year and engine i believe.
Idle issues, clear smoke, hesitation and DPF error codes.
Hope you get it resolved!

Thanks, good luck with yours, it sounds the same only I'm getting no error codes. When I find out what the problem is I'll post the answer on here, hopefully it might help other people with a similar problem.

 

[gupsterg]

a slight hissing noise, like air was being expelled for about 6 seconds. Is this usual after switching the engine off?

The slight hissing noise can be the air con circuit after shutdown ...

Audi’s attitude of ‘no error codes = nothing wrong’ has been a big disappointment.

Viewing of measuring blocks using VCDS or dealer VAS diagnostics machine maybe what you require to pin point problem ...

Boost leak as black smoke is poor combustion.

Thanks NHN. I guess that could be a simple fix, tricky to find, and something so basic any garage should have considered?!

Perhaps ask for a pressure test to be done on charge air system ...

 

[NHN]

You can actually, on some cars, activate the charge air system with vcds to try & help find leaks.

 

[gupsterg]

NHN I think you referring to the elements which can be tested by doing an output test in module 01? or do you mean it will check the intercoolers and related hoses? as that's what I referring to when stating get a pressure test done ...

 

[NHN]

Well there are a few tests, the basic setting in engine is one yes, but also a pressure/smoke tester is also a good one to use, I had the pleasure of using the dealer tool on my car on a weekend, nice piece of kit, no ****** leaks though lol.

 

[margin-walker]

I have a new symptom: starting the car! ​I put the key in the ignition to start the car and it didn't start first time, I had to keep the key turned for a second longer the second time and it started. It's never done this before. Does this provide any more insight?! I'm going to search the forums now. Thanks for all of your help.

 

[barryA4]

Hi margin-walker,
did you ever get to the root cause of this problem. I have recently purchased a 2005 2.0 A4 tdi 140BHP with the same symptoms. Dealer is now refusing to accept that car has an issue, even after taking the salesman out for a test drive to show him and him then agreeing that car needs to be looked at again. Its apparently been sent to 3 different garages and is now due to go to Glasgow Audi for another opinion....but im not holidng much hope, as there will be no fault codes to report.
thanks in advance

 

[mm707]

Hesitation at around 1600 - 1800 rpm is most likely the vacuum actuator which controls the flaps in the inlet manifold. About £10 for a new one. They have a diaphragm inside which splits

 

[margin-walker]

Hi BarryA4. Yes I did get the bottom of the problem, despite several Audi garages and independent diagnostic experts saying there was no problem or error code. Scans with VCDS came up with the following error code which mystified everybody:


000000 - SAE - Reserved by Document ISO 15031-6
P0000 - 006 - 2005 - Intermittent
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 37
Reset counter: 40
Mileage: 0 km
Time Indication: 0

Freeze Frame:
RPM: 1984 / min
Torque: 144.0 Nm
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Raw, Form. N / A: 000 000 000

--------------
So I took my car (with some idea of what the problem might be after a lot of research using Google translate!) to a remapping expert who confirmed that the previous muppet owner had downloaded some crap software off the Internet and tried to remap the car/delete dpf himself!! The engine map on the car was the worst he had ever seen, so he remapped my car again and it's been a completely different animal since. More like the car Audi should have made to start with. So do check your error codes with VCDS and if you have the same error I had then that is your problem.

The vacuum actuator is another culprit but that nearly always throws obvious error codes such as:

000665 - Boost Pressure Regulation
P0299 - 006 - Control Range Not Reached - Intermittent

 

[barryA4]

Hi BarryA4. Yes I did get the bottom of the problem, despite several Audi garages and independent diagnostic experts saying there was no problem or error code. Scans with VCDS came up with the following error code which mystified everybody:


000000 - SAE - Reserved by Document ISO 15031-6
P0000 - 006 - 2005 - Intermittent
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 37
Reset counter: 40
Mileage: 0 km
Time Indication: 0

Freeze Frame:
RPM: 1984 / min
Torque: 144.0 Nm
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Raw, Form. N / A: 000 000 000

--------------
So I took my car (with some idea of what the problem might be after a lot of research using Google translate!) to a remapping expert who confirmed that the previous muppet owner had downloaded some **** software off the Internet and tried to remap the car/delete dpf himself!! The engine map on the car was the worst he had ever seen, so he remapped my car again and it's been a completely different animal since. More like the car Audi should have made to start with. So do check your error codes with VCDS and if you have the same error I had then that is your problem.

The vacuum actuator is another culprit but that nearly always throws obvious error codes such as:

000665 - Boost Pressure Regulation
P0299 - 006 - Control Range Not Reached - Intermittent

Hi , and thank you for the replies.
I am expecting to hear back from garage today regarding its little visit to Audi Glasgow. I am not very hopeful that they will have found the root cause.
I will check the car when its returned, and get back to you. Does VCDS Lite allow for error codes to be displayed. I havent used it before.
I will post an update later to let you know what their verdict was. My suspicion is that they will carry out and remap at Audi just to eliminate any doubt on that side of things....but just tell me that they cant find an issue. Just as they have been doing since the day after i bought the car.

cheers again guys

 

[barryA4]

Picked car up last night after Audi diagnosed the issue as an intermittent EGR valve fault. No codes on VCDS but mechanic was sure that was the problem. Car drove perfectly for the 70 miles home and so far looks to be resolved, but time will tell. I have the suspect EGR in my possession and yes it is thick with crusty/oily carbon. Think i will clean it out and keep it as a spare....just in case.
I will keep you all posted on how it runs from now.

thanks again for the replies

 

[barryA4]

Oh, one more question......how do i tell if my car has a DPF. I suspect it doesn't, as I wouldn't have had a heap of black smoke (unless the DPF is burst) but just wanted to check.
thanks again

 

[barryA4]

Well, inspected the faulty EGR valve and found that the flap part had detached from the spindle....looked like a dodgy weld when manufactured.
So at least i found something......however, after a week of driving when all seemed to be great, the car began slightly stuttering again. Predominantly in 4th gear around 2k rpm. But today after pulling off the dual carriageway, and drawing away from a junction, the car stuttered at 2k rpm through the gears from 2nd up to 5th ???
Recently i have noticed a fuel leak at the filter breather union fitting ( the silly plastic fitting ) which is beginning to smell stronger like its getting worse. My question is, would this weeping fuel leak contribute to the stuttering issue that i am seeing again ?
I really am at my wits end with this car and any advice would help.

 

[barryA4]

Hi BarryA4. Yes I did get the bottom of the problem, despite several Audi garages and independent diagnostic experts saying there was no problem or error code. Scans with VCDS came up with the following error code which mystified everybody:


000000 - SAE - Reserved by Document ISO 15031-6
P0000 - 006 - 2005 - Intermittent
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 37
Reset counter: 40
Mileage: 0 km
Time Indication: 0

Freeze Frame:
RPM: 1984 / min
Torque: 144.0 Nm
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Text: Kein MEASVALUE verfuegbar
Raw, Form. N / A: 000 000 000

--------------
So I took my car (with some idea of what the problem might be after a lot of research using Google translate!) to a remapping expert who confirmed that the previous muppet owner had downloaded some **** software off the Internet and tried to remap the car/delete dpf himself!! The engine map on the car was the worst he had ever seen, so he remapped my car again and it's been a completely different animal since. More like the car Audi should have made to start with. So do check your error codes with VCDS and if you have the same error I had then that is your problem.

The vacuum actuator is another culprit but that nearly always throws obvious error codes such as:

000665 - Boost Pressure Regulation
P0299 - 006 - Control Range Not Reached - Intermittent

Do you know the part number for the vacuum actuator you mentioned? Thanks in advance

 

[barryA4]

Do you know the part number for the vacuum actuator you mentioned? Thanks in advance

Sorry to bump this thread guys but I'm at my wits end. Car still "misfiring" at around 2k rpm... Garage say they're is no fault with the car and it drives as expected. Told me there is nothing they can do to fix a fault that doesn't show itself. Like I mentioned previously, the egr had been replaced and fuel filter done also. Don't know where next. Any help would be appreciated.

 

[mm707]

Vacuum actuator part number is S03G129061C , about £10 from TPS and about £5 for the gasgets.

Easy to fit, fixed my hesitating at 1800 rpm

 

[barryA4]

Thanks for the reply...did the actuator not throw up any fault codes though?
I will get one ordered now.

 

[barryA4]

mm707, does the BLB engine have this actuator ?

 

[mm707]

mm707, does the BLB engine have this actuator ?

Not sure Barry, mine is a brd.

This pic shows it, take the cover off the top of the engine and it's near the front just to the left, it's just to the side of the inlet manifold.

 

[barryA4]

Thanks for the info... I will have a look tomorrow.
Hesitation seems to be getting worse... Just collected car from dealer again after finding no issue with the car. Drive it 60 miles up the road and the hesitation is sporadic but more noticeable when it does it. Can even hear the engine when it does it...sounds like a voot, voot voot to accompany the stutter. Beginning to think it's turbo related but I really don't have a clue. Does anyone know a good experienced Audi diagnostician in Dundee area ?

 

[csm]

My cars a BRD and I fitted the actuator........... still hesitates on and off and car sounds very hoarse and heavy breathing.... can hear the breathing like a back pressure out of airfilter box........ Although I have covered 40k in a year and a half the car has been a pain in the **** from day one, never throws up codes on diagnostics etc, thinking about getting rid of mine and going back to Ford that's never gave me problems.

 

[SDHA4SLine]

Not sure Barry, mine is a brd.

This pic shows it, take the cover off the top of the engine and it's near the front just to the left, it's just to the side of the inlet manifold.
View attachment 47756

Barry, be aware you have to remove the inlet manifold to replace this actuator. Its not a hard job but can be a bit fiddly and blinking messy. Also if you didn't already know there is a little hidden screw inside the inlet manifold (you'll see it if not covered in crud! when you remove the egr valve) that catches a few people out when they try to remove the manifold.

On the up side it'll be good to whip off the manifold in order to give it a good clean out mine was absolutely full of crud.

This link may or may not be helpful for you...

http://www.audi-sport.net/xf/threads/a6-2-0-tdi-inlet-manifold-actuator.176221/

 

[barryA4]

Barry, be aware you have to remove the inlet manifold to replace this actuator. Its not a hard job but can be a bit fiddly and blinking messy. Also if you didn't already know there is a little hidden screw inside the inlet manifold (you'll see it if not covered in crud! when you remove the egr valve) that catches a few people out when they try to remove the manifold.

On the up side it'll be good to whip off the manifold in order to give it a good clean out mine was absolutely full of crud.

This link may or may not be helpful for you...

http://www.audi-sport.net/xf/threads/a6-2-0-tdi-inlet-manifold-actuator.176221/

Thanks for the heads up.... The link photos don't look like my blb engine though. I can really see an actuator like in the picture.... Am I missing something else? Sorry if I'm sounding dumb.

 

[SDHA4SLine]

Thanks for the heads up.... The link photos don't look like my blb engine though. I can really see an actuator like in the picture.... Am I missing something else? Sorry if I'm sounding dumb.

Nope if it looks like the one in the picture and its attached to your inlet manifold then that's your fella.

Maybe upload a photo of your engine bay if you want reassurance of the actuator. Come to think of it, once you have the new one in your hand that should be enough reassurance for you.

 

[barryA4]

Nope if it looks like the one in the picture and its attached to your inlet manifold then that's your fella.

Maybe upload a photo of your engine bay if you want reassurance of the actuator. Come to think of it, once you have the new one in your hand that should be enough reassurance for you.

Sorry I meant "can't" really see a actuator. Will check again in morning and upload a picture too just for confirmation.
Thanks again

 

[barryA4]

Sorry I meant "can't" really see a actuator. Will check again in morning and upload a picture too just for confirmation.
Thanks again

No sign of an actuator I'm afraid.... Unless I'm missing it.

 

[SDHA4SLine]

How very strange! Not sure if you've already said but what engine code is yours? Like you say can't see an actuator there, or at least where it is on my BRD. Everything else looks identical to mine

 

[barryA4]

How very strange! Not sure if you've already said but what engine code is yours? Like you say can't see an actuator there, or at least where it is on my BRD. Everything else looks identical to mine

Mines BLB :-(

 

[SDHA4SLine]

Well hopefully someone with more knowledge can chip in here.

Only thing that I can think of (and its a slim chance this may be it) I have read that apparently the manifold flaps can be mapped out so maybe this is the case for yours and the actuator was simply removed. Although I'm not sure how this works as on mine there is only a vacuum hose connected to it and no electrical connection so how it gets mapped out is beyond me!

Other than that maybe it's just not on the earlier engines.

Sorry I can't be of more help.

 

[barryA4]

Well hopefully someone with more knowledge can chip in here.

Only thing that I can think of (and its a slim chance this may be it) I have read that apparently the manifold flaps can be mapped out so maybe this is the case for yours and the actuator was simply removed. Although I'm not sure how this works as on mine there is only a vacuum hose connected to it and no electrical connection so how it gets mapped out is beyond me!

Other than that maybe it's just not on the earlier engines.

Sorry I can't be of more help.

No worries buddy, thanks for all your suggestions though. Car is going round to a local technician on Monday.... He seems clued up on Audi's so fingers crossed. He feels it might just be the inlet manifold needing cleaned out.
Well let you know how it gets on.