Hi all,

My father in law's DV6 MK2.5 is already causing problems and he's not had it 2 months yet! 

Generally speaking the car drives nicely (idles smoothly and pulls well etc) but often after a good hour plus on the motorway, the EML will illuminate but the car will continue to drive normally.  Cycling the ignition has so far always cleared the EML.

I plugged Forscan in yesterday and got the following DTC's (the DTC log is at the end of the post and judging by the description in the Forscan log, some of the DTC's weren't "active" anymore at the point when I ran the DTC scan).

Forscan is nice enough to give potential reasons for each DTC but due to the large number of related DTC's it leaves quite a long list and I'm not so familiar with the subtleties of the DV6 engine.  Do any of the guys with personal experience of this engine have any recommended starting points having looked at the description above and the DTC's that have been triggered.

Incidentally I've cleared the DTC's and none have returned so far, although the car has only made short journeys since then.  Also the fuel filter was changed 2-3 weeks ago, I plan on cleaning the MAF on Saturday with MAF cleaner and the clips which lock this little 90 degree pipe in place have been snapped so the "fit" isn't quite a tight as it should be (a small amount of oil mist appears to have been escaping) and I've ordered a replacement part which will also be hopefully getting fitted at the weekend.

Is it likely that this possible minor air leak may have been causing all the DTC's below or is it more likely that it just isn't helping and the root cause will probably be elsewhere?

Thanks in advance for any suggestions/advice.

===PCM DTC P0234-A0===
Code: P0234 - Turbo/Super Charger Overboost Condition

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is On for this DTC

Module: Powertrain Control Module

Diagnostic Trouble Code details

Turbo/Super Charger Overboost Condition

unexpected high boost pressure detected during acceleration

This DTC may be caused by :

* Calibration data may be out of date

* Vanes on the turbocharger sticking closed

* Vacuum supply to the turbocharger not venting

* The engine speed was excessive due to incorrect gear selection.

Check to determine if there is a later calibration which addresses 
the customer concern.

Do not update the PCM if the later calibration does not address the customer's concern.

Clearing DTCs will remove all Continuous Memory DTCs this may reduce the effectiveness of running future diagnostics.

if a later calibration has been programmed, clear the continuous memory DTCs

drive the vehicle on the road performing a varied drive cycle, gear changing regularly causing low to high engine RPM, where possible drive up and down hills

Read DTCs

Are the DTCs still present?

For further diagnostic information refer to the appropriate section of eTIS.

===END PCM DTC P0234-A0===

===PCM DTC P0299-20===
Code: P0299 - Turbocharger/Supercharger Underboost

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Powertrain Control Module

Diagnostic Trouble Code details

Turbocharger/Supercharger Underboost

unexpected low boost pressure detected during acceleration

This DTC may be caused by :

* Calibration data may be out of date

* Insufficient boost levels do not necessarily indicate a bad turbo charger, and may result from intake (charge air cooler, charge air cooler tube, or silicone cuffs) air leaks, or exhaust (V-band, exhaust manifold, or Y-pipe) leaks.

* Air intake restriction

* Vacuum Leakage

* Damaged or contaminated connector

* Contaminated MAF

* blocked vacuum hoses to turbo or wastegate

* Check the PCM for the latest calibration.

* check for leaks in the boost pressure circuit

* Check vacuum and electrical connections to the EVR.

* Check for vacuum leaks.

* Inspect connectors for signs of damage, water ingress, corrosion, etc.

* check the MAF for dirt and contamination

* Check the vacuum hose routing; if you are in doubt, refer to the appropriate service literature.

For further diagnostic information refer to the appropriate section of eTIS.

===END PCM DTC P0299-20===

===OBDII DTC P0234-C===
Code: P0234 - Turbo/Super Charger Overboost Condition

Status: 
 - Confirmed - malfunction is confirmed 

Module: On Board Diagnostic II

Diagnostic Trouble Code details

Turbo/Super Charger Overboost Condition

unexpected high boost pressure detected during acceleration

This DTC may be caused by :

* Calibration data may be out of date

* Vanes on the turbocharger sticking closed

* Vacuum supply to the turbocharger not venting

* The engine speed was excessive due to incorrect gear selection.

Check to determine if there is a later calibration which addresses 
the customer concern.

Do not update the PCM if the later calibration does not address the customer's concern.

Clearing DTCs will remove all Continuous Memory DTCs this may reduce the effectiveness of running future diagnostics.

if a later calibration has been programmed, clear the continuous memory DTCs

drive the vehicle on the road performing a varied drive cycle, gear changing regularly causing low to high engine RPM, where possible drive up and down hills

Read DTCs

Are the DTCs still present?

For further diagnostic information refer to the appropriate section of eTIS.

===END OBDII DTC P0234-C===

===OBDII DTC P0299-P===
Code: P0299 - Turbocharger/Supercharger Underboost

Status: 
 - Pending - malfunction is expected to be confirmed 

Module: On Board Diagnostic II

Diagnostic Trouble Code details

Turbocharger/Supercharger Underboost

unexpected low boost pressure detected during acceleration

This DTC may be caused by :

* Calibration data may be out of date

* Insufficient boost levels do not necessarily indicate a bad turbo charger, and may result from intake (charge air cooler, charge air cooler tube, or silicone cuffs) air leaks, or exhaust (V-band, exhaust manifold, or Y-pipe) leaks.

* Air intake restriction

* Vacuum Leakage

* Damaged or contaminated connector

* Contaminated MAF

* blocked vacuum hoses to turbo or wastegate

* Check the PCM for the latest calibration.

* check for leaks in the boost pressure circuit

* Check vacuum and electrical connections to the EVR.

* Check for vacuum leaks.

* Inspect connectors for signs of damage, water ingress, corrosion, etc.

* check the MAF for dirt and contamination

* Check the vacuum hose routing; if you are in doubt, refer to the appropriate service literature.

For further diagnostic information refer to the appropriate section of eTIS.

===END OBDII DTC P0299-P===

===PCM DTC P2196-26===
Code: P2196 - HO2S11 not switching correctly. Sensor indicates rich.

Additional Fault Symptom:
 - Signal is Below Minimum Threshold

Status: 
 - Previously Set DTC - Not Present at Time of Request
 - Malfunction Indicator Lamp is Off for this DTC

Module: Powertrain Control Module

Diagnostic Trouble Code details

HO2S11 not switching correctly. Sensor indicates rich.

Low Manifold Vacuum on TMAP systems only.

High Fuel Pressure

This DTC may be caused by :

* Air intake restriction

===END PCM DTC P2196-26===

 

Oh dear, the focus forum is filling with broken DV6 threads again!

That elbow clip is broken on most of them these days.  Can't say I've seen it causing faults though, usually just sending wafts of burnt oil through the cabin.  Replaced mine for the same reason a few weeks ago.

Overboost is likely to be the turbo vanes sticking - it's a 110 yeah?  As the 90 uses wastegate instead.  Code will probably return if you give it a hard boot down a slip road.

Not sure about the 02 sensor fault, mine doesn't have one but they may have introduced it with the cDPF models.

Yeah, it's the higher output version with cDPF (2011 plate), once I've done the minor bits I plan on doing anyway, if that doesn't resolve it I'll have to see about taking a look at the turbo. 

There was a 2 year gap in the service history for the immediate period before he bought it so the oil may well have got pretty crappy in that time (and yes I really tried to steer him away from a DV6 that might not have had an oil change in over 2 years, but I failed!).

In terms of being able to see the vanes, is it easy enough to get access to that part of the turbo without removing it?

You would need to remove the turbo to be able to separate it and see the vanes.  I think you can access the actuator arm while still on the car though, it's underneath the turbo but there may be enough space, if you can disconnect that you should be able to push and pull it to feel how smooth or stiff the vane action is.  Or try one of those cans of stuff that is meant to clean the vanes, I don't know how effective they are.  It may just be that the car was driven too 'sedately' by the previous owner causing the vanes to stick until they got a hard push so I'd wait until the code returns or before there's a noticeable issue (lots of lag or lacking top end) before putting too much effort into it.

1 hour ago, TomsFocus said:

You would need to remove the turbo to be able to separate it and see the vanes.  I think you can access the actuator arm while still on the car though, it's underneath the turbo but there may be enough space, if you can disconnect that you should be able to push and pull it to feel how smooth or stiff the vane action is.  Or try one of those cans of stuff that is meant to clean the vanes, I don't know how effective they are.  It may just be that the car was driven too 'sedately' by the previous owner causing the vanes to stick until they got a hard push so I'd wait until the code returns or before there's a noticeable issue (lots of lag or lacking top end) before putting too much effort into it.

Just trying to keep the father in law sweet.  Finally got him over from BMW and he picks the bl**dy DV6 engine!  Basically he saw my 12 year old 1.8 TDCi still going strong at 140K miles on original clutch, DMF, turbo, high pressure fuel pump and injectors and thought that'll save me loads of money in repair bills, plus it's good to drive, then picks the DV6?!?

I do however take the point that it might not be worth worrying about too much whilst the car still drives properly.

On a related note, I had the standard Terraclean done on mine a couple of years ago and it made a big difference to the engine, it seems they also do a separate service aimed squarely at the EGR and turbo so might have a look at that.

Tbf, you've done well with a 1.8 TDCi getting to that mileage without injector or DMF issues.   They're not all as reliable unfortunately, when I was looking about 3 years ago there were loads being sold with injector issues.  I can't really comment though, I did the same as your FIL, needed something ultra reliable...but also cheap to tax & fuel and with reasonable power...and needed to be Focus sized for ride comfort and practicality.  Petrols were obviously out.  The 1.8 TDCis appeared to be unreliable and more expensive to run (I realise this isn't your experience!).  2.0 TDCis in Titanium spec were too expensive to buy and cost more to run.  Just left with the DV6...  Tried a 90ps version due to the extra reliability but it was just so slow.  So ended up with probably the least reliable engine in the end, the £30 tax didn't make up for it lol...  

Must admit I'm sceptical about Terraclean, but if it worked for you then it might be worth a go.

1 hour ago, TomsFocus said:

Tbf, you've done well with a 1.8 TDCi getting to that mileage without injector or DMF issues.   They're not all as reliable unfortunately, when I was looking about 3 years ago there were loads being sold with injector issues.  I can't really comment though, I did the same as your FIL, needed something ultra reliable...but also cheap to tax & fuel and with reasonable power...and needed to be Focus sized for ride comfort and practicality.  Petrols were obviously out.  The 1.8 TDCis appeared to be unreliable and more expensive to run (I realise this isn't your experience!).  2.0 TDCis in Titanium spec were too expensive to buy and cost more to run.  Just left with the DV6...  Tried a 90ps version due to the extra reliability but it was just so slow.  So ended up with probably the least reliable engine in the end, the £30 tax didn't make up for it lol...  

Must admit I'm sceptical about Terraclean, but if it worked for you then it might be worth a go.

The injector issues aren't inherent to the engine and are usually confined to 2009 batch that affected all Ford models that used the Lynx engine.  Regarding Terraclean my engine was well coked up, lumpy at idle, didn't like coasting anymore in 1st/2nd (in traffic) and used to leave lots of soot behind when booted.  The difference immediately after the Terraclean was VERY noticeable, even the wife noticed the car was driving better and she didn't even know I'd spent £120 getting it done 

Some people (I guess) will go for a Terraclean rather than deal with an underlying issue, in these cases I'd expect someone to be disappointed.

Ah, that would make sense about the injectors, I'm not a fan of prefacelifts (no offence lol ) and couldn't afford anything newer than 59 plate so was literally just looking at 08/09 models at the time!

 

2 hours ago, TomsFocus said:

Ah, that would make sense about the injectors, I'm not a fan of prefacelifts (no offence lol ) and couldn't afford anything newer than 59 plate so was literally just looking at 08/09 models at the time!

 

None taken, only a blind person could seriously try and say that a MK2 is better looking from the front than a MK2.5.  I agree that the face lifted Focus is much better looking and the interior is also quite a lot nicer when you look closely (red display/ambient button lighting rather than 1980's green, satin silver radio rather than the square dark grey 1 out of a Transit van, nicer upholstery and even the soft touch plastics have been made that little more pleasant). 

My issue was also budget i.e. at the time I bought it 6-7 years ago the MK2.5 was WAY outside my budget, I specifically wanted to 1.8 TDCi to avoid a DPF and certainly wasn't going to risk buying one with the dodgy injectors (late 2008 to 2009 models).

4 hours ago, 1979Damian said:

I specifically wanted to 1.8 TDCi to avoid a DPF

I also bought my 1.8TDCI 6 years ago, and I had to search quite a wide distance range to find one. It was the no DPF that was the reason. I knew nothing of the 08/09 injector problem then, but those years were way out of my budget, luckily!

On the DTCs, it boils down to: Turbo Overboost & Underboost, and Oxygen sensor reading rich.

An air leak could cause both Underboost & O2 reading rich, but seems less likely to cause Overboost. And it was the Overboost that had the MIL on for it.

Sticky turbo actuator, or dodgy electrics in or to the actuator, could give both the Overboost & Underboost, then Underboost, with consequent low air flow, could in turn cause the O2 rich error.

But there are probably other causes, dodgy MAP (or its connections) is one.

A couple of runs with Forscan in data log mode might help (recording MAP, actuator drive/demand, rpm, throttle, no of DTCs, and maybe one or two more things). But it could take a while to track it down, unless it gets much worse.

Interesting about the Terraclean. My view on all these cleans, from a Wynns spray, to a £120 garage job, is they will do nothing unless there is an actual, real problem that they are designed & able to cure. So it sounds like you had exactly that, and it did its job well.

On my 1.8, I can fairly reliably get Underboost (P0299) if I open the throttle too wide at below about 1500rpm (50mph in 5th). Once above about 1700rpm, it is fine on full throttle & gives 2.2 to 2.4 Bar boost pressure, which seems right. I am just putting up with it until I think or hear of some way to identify the fault. It might be a slight sticky spot on the turbo vanes. Wide throttle at 1500rpm is a bit harsh on the DMF & engine anyway, so I just have to avoid being lazy, and change down!