Many thanks for posting the cause and solution to your problem, not enough people do that!

Happy new year!

 

FOUND IT!!!! At long last I have a complete fix for this problem.

A few days ago the old problem returned, over 50mph, foot down, P010f and limp home mode. As luck would have it, it was dark when I went looking in the engine bay, because it was only by using a torch that the small glint of metal appeared where it shouldn't - a big crack in the throttle body actuator thingy, which I then wiggled and it came away. Photo of the damage:

(The sparkly effect is the flash reflecting off oil etc)

Air under turbo pressure leaks out of the hole causing an imbalance between mass air flow and the amount going into the engine - hence P010f.

Since having this repaired, ALL my P010f symptoms have gone completely. There must have been a hairline crack, possibly caused when the inlet manifold was replaced, which suddenly failed properly last week giving rise to the more serious symptoms. I'm SO glad to have this resolved, and thought I would at least do you all the courtesy of letting you know what the problem really was.

To sum up what most likely caused all of this in the first place::

1. EGR valve failure, valve stuck partially open.

2. Defrost car while idling for a long period - EGR gases melt part of inlet manifold

3. Inlet manifold replaced (£££), mechanic perhaps knocks throttle body during the process causing a small crack

4. Many months of getting P010f and limp-home mode but only under very specific, high-load and high-speed conditions that garages either can't or won't reproduce

5. Throttle Body finally fails in a visible way causing P010f and limp-home almost all the time

6. Throttle body replaced (£££!), all previous P010f symptoms now gone.

Thanks again to everyone who contributed to this thread, hopefully there is something useful in here for others to take on board when trying to resolve similar issues. Oh - and if you want to prevent this happening in the first place on this engine, BLANK YOUR EGR. The blanking plate costs a fiver off Ebay and can be fitted in 5 minutes. If I'd fitted one a year ago it would have saved me well over £800 in parts and labour :eek13: It causes no evil side effects, there is no EML and no fault codes, and it passed its last MOT with the plate fitted.

Cheers,

Moosepig

 

Holy thread resurrection, batman!

Just a short note to thank everyone who's contributed. I never really got to the bottom of this, and have simply adapted my driving style on the motorway to prevent the problem occurring. It remains a conundrum. I could have thrown money at it but with no guarantee of a resolution I decided I'd rather spend the money on beer.

As an aside, don't bother buying cheap aftermarket MAF sensors. Mine failed the other day after, what... 6 months of use? giving P010F every single time I tried to accelerate from any speed in any gear: luckily FORScan identified the problem immediately. As it turned out, I'd swapped the original MAF sensor for the aftermarket one in my initial attempts at resolving the original issue (before I got FORScan), and never put the (fully working) original back. So the fix this time was a simple swap back to the original sensor.

Cheers all :beer:

 

I just performed reset operation to the DPF learned values and the PID's for "demanded" and "successful" regens, various soot load indicators and a PID which indicates "Total fuel quantity consumed after last filter cleaning" were all set to "0".

Those are all the DPF related PID's I've found on my car. Interestingly, there is no PID indicating the ash quantity accumulated inside the filter (VW's do have it, and when it hits the predetermined threshold value, you need to replace the filter).

I do not know for sure but it seems that if the ECU considers that the filter is clogged, you cannot reset the learned values w/o the Dealership scan tool.

 

I'd say that NOFRE is a count of failed regens since last reset of the DPF learnt values. Or if the values have never been reset, then it's a count starting from when the car has been taken into use.

I've never actually seen NOFRE on anything other than 0 on my 2008 model. NORFARD seems to be...odd as well. It can finish a regen and sometimes reset to 0, other times it'll increment. Never seems to go above 3.

On my 2.2 (my. 2009) I've seen values beyond 20. Could it be different on different ECU versions?

Sorry guys - I must rectify false info I've given .

My car does not have NOFRE. Instead there are PID's for "demanded" and "successful" regens, and I must have had that difference in my mind. The current values for those PID's are 69 and 58 - I've reset the learnt values some 30,000 km's ago.

I believe that those PID's must have been reset to zero, since my average interval between regens is approx. 480 km's.

 

I'd say that NOFRE is a count of failed regens since last reset of the DPF learnt values. Or if the values have never been reset, then it's a count starting from when the car has been taken into use.

I've never actually seen NOFRE on anything other than 0 on my 2008 model. NORFARD seems to be...odd as well. It can finish a regen and sometimes reset to 0, other times it'll increment. Never seems to go above 3.

On my 2.2 (my. 2009) I've seen values beyond 20. Could it be different on different ECU versions?

Wouldn't surprise me at all. There were some pretty significant changes on the facelift version too.

 

I'd say that NOFRE is a count of failed regens since last reset of the DPF learnt values. Or if the values have never been reset, then it's a count starting from when the car has been taken into use.

I've never actually seen NOFRE on anything other than 0 on my 2008 model. NORFARD seems to be...odd as well. It can finish a regen and sometimes reset to 0, other times it'll increment. Never seems to go above 3.

On my 2.2 (my. 2009) I've seen values beyond 20. Could it be different on different ECU versions?

 

Any progress?

Sadly not. I've not had the time to investigate the variable vane theory yet. I continue to use the car daily, just taking care not to floor it when accelerating onto the motorway, and I'm managing to remain free of EML incidents so far.

Thanks for enquiring, though - I was aware that I'd probably let this thread go quiet for too long, so thanks for the bump

I'll be back on here as soon as I get a chance to make any progress.

Cheers,

Moosepig

 

I'd say that NOFRE is a count of failed regens since last reset of the DPF learnt values. Or if the values have never been reset, then it's a count starting from when the car has been taken into use.

I've never actually seen NOFRE on anything other than 0 on my 2008 model. NORFARD seems to be...odd as well. It can finish a regen and sometimes reset to 0, other times it'll increment. Never seems to go above 3.

 

First three are seconds past certain temperature overheating limits

DP_DPF is the pressure difference over the DPF. Important one. Should usually be less than 2kPa (at idle), the higher the more likely it needs a regen.

DSLCR is mileage since last complete regeneration

DSLRT is mileage since last attempted regen

NOFRE is a count of failed regens since last regen, not sure I trust it as being right though.

NORFARD is similar to NOFRE, again don't really trust it.

TESLRT is time since last regen in minutes.

Awesome, thanks.

 

I'd say that NOFRE is a count of failed regens since last reset of the DPF learnt values. Or if the values have never been reset, then it's a count starting from when the car has been taken into use.

 

First three are seconds past certain temperature overheating limits

DP_DPF is the pressure difference over the DPF. Important one. Should usually be less than 2kPa (at idle), the higher the more likely it needs a regen.

DSLCR is mileage since last complete regeneration

DSLRT is mileage since last attempted regen

NOFRE is a count of failed regens since last regen, not sure I trust it as being right though.

NORFARD is similar to NOFRE, again don't really trust it.

TESLRT is time since last regen in minutes.

 

Sorry to jump in but can anyone clarify what each of the readings in the attached picture mean? I want to check my DPF with FORscan but not wure what the values actually mean.

 

Any progress?

 

I believe the only way to verify whether the vanes move freely is to remove the vane actuator and then by fingers move the vane shaft and feel if it moves without sticking.

 

Tech from Celtic Tuning assures me that the remap would not mask fault codes, so intermittently sticky turbo vanes are now favourite.

Is there an easy way to check this before I go down the Revive route? I don't have access to garage facilities or a ramp/pit for access to the turbo, so I don't want to have to remove it.

Cheers,

Moosepig

 

Well the long drive did prompt a regen, but it hasn't helped.

Good call re the turbo vanes and lack of DTCs, I'll pursue that line of investigation further.

Cheers,

Moosepig

 

I would never ever do this myself: http://www.audi-sport.net/xf/threads/un-sticking-your-tdi-vnt-turbo-vanes.107121/

But there are those who dare and those who don't.... :smoking:

 

Just thinking over the problem...

The PCM commands the vanes to reduce boost, and nothing happens except that the vane voltage changes. Would this mean that the vanes do not move freely and need cleaning? On the other hand, no turbo/boost related DTC - beats me :kaffeetrinker_2: .

EDIT: I think I got it.... there are no charge pressure DTC's because of the remap. The remap typically includes that the threshold limits are altered so that high boost pressures can be utilised.

 

Odd, isn't it? I don't get any DTCs other than P010F either - no DPF codes or turbo codes. And, despite having blanked the EGR, no EGR codes either despite the common wisdom being that I would get DTCs by doing that.

I tried changing the display units of the DP_DPF PID but the values it was indicating worked out to be identical whether it was in bar, psi or kPa (I stuck them through a unit converter on t'interwebs)

Did a long motorway drive in 4th yesterday, hopefully it's done a DPF regen so I can eliminate it from the enquiry (or identify yet another expensive part that needs replacing!) won't get a chance to find out until Sunday at the earliest.

EGR Blank hasn't thrown any sort of fault code at all on mine since putting it in early December.

Those pressures definitely sound like either a blocked DPF, burnt hoses or a bad sensor.

Just keep in mind a long run itself won't do anything for the DPF other than block it more. A regen only happens when the ECU commands it (no passive regeneration). If the run was long enough there's a good chance it will have commanded one though. You'll need to recheck the DSLCR PID again. Interestingly despite your DPF readings being quite high your mileage between regens seems quite high. Mine is every 375 miles. What's the reading for the average distance between regens PID?

 

Yeah, the vane adjustment is there to control the boost level at various load conditions. Since the PCM is trying to reduce the boost, I believe it considers either of the MAF/MAP values too high and wants to adjust the value down.

There is one trick you could try out just to get more understanding to the problem. If your MAF is of the typical construction where part of the charge air goes through a slot in the MAF sensor, you could partly cover the slot w/ adhesive tape, thereby fooling the PCM to believe that the amount of air entering the engine is smaller than it actually is. This would change the MAF/MAP ratio the PCM sees.

This is a trick used to pass through the MOT smoke test, in case there is excessive smoke (PCM reduces fuel quantity, which leads to a leaner mix and hence less soot in the exhaust gas).

 

Odd, isn't it? I don't get any DTCs other than P010F either - no DPF codes or turbo codes. And, despite having blanked the EGR, no EGR codes either despite the common wisdom being that I would get DTCs by doing that.

I tried changing the display units of the DP_DPF PID but the values it was indicating worked out to be identical whether it was in bar, psi or kPa (I stuck them through a unit converter on t'interwebs)

Did a long motorway drive in 4th yesterday, hopefully it's done a DPF regen so I can eliminate it from the enquiry (or identify yet another expensive part that needs replacing!) won't get a chance to find out until Sunday at the earliest.

The turbo variable vane voltage changing before the MAF/MAP dip is most confusing, primarily because I have no idea how the PCM decides what to do with the turbo vanes or why. It could be a cause... or just another symptom, but happening slightly earlier. Presumably the variable vane is a way of preventing boost levels geting too high without restricting exhaust flow, but why it should happen on full beans is a mystery, and if the PCM is commanding it then why should the MAP/MAF pressure dip be unexpected and cause P010F? I'm stumped so far.

Dodgy connector on the turbo variable vane controller??

Thanks for all help so far folks - I had a feeling that this wouldn't be simple.

 

A couple of notes...

I believe there might be a bug in ForScan. If the DPF pressure loss of 6.8 psi was true, it would mean 47 kPa - which I fail to believe. Perhaps the values are in kPa anyway?

According to the graphs, the turbo adjustment has been reducing the charging already a while before the problem occurs (the vane adj. voltage is dropping in each graph). But there is no effect in MAP/MAF values (the MAF actually seems to go slightly up even though the ECU tries to reduce it?).

 

0.2 at idle when cold.

Will try a regen when I get a chance.

 

0.2 psi, hot engine. Only reads in steps of 0.1 psi.

Will try to get a cold reading in the morning.

Cheers,

Moosepig