C5 2008 (X7 ?) Turbo Fault

[moizeau]

You don't need to drive the car. The vacuum pipes and any electricals will need to be connected.

[Paul-R]

The two problems are becoming a bit confusing. Perhaps a Mod could separate the heater fan into a separate thread?

[MikeT]

I'm only just catching up on this thread...

I would imagine you could connect the air doser plugs and observe them moving after starting the engine? I also believe they park or even cycle then park, after engine off though there could be a minute delay to see that happen. Alternatively, you can use Lexia actuator tests without the need to run the engine.

[GiveMeABreak]

Ok, so this Topic has been split into 2 - please keep this thread on track regarding the original Turbo issues.

The blower / heater issue now has a separate topic located here:

C5 X7 2008 Heater Control Blower Motor Topic

Ta muchly

[moizeau]

I believe the car has changed hands, so we'll have to see if the new owner continues or not. Mike, the actuator tests in Diag do need the engine to be started for 15 secs to get a vacuum, not sure about the cycling, the actuator test would be the way to go, but we'll have to wait and see.

[Paul-R]

I believe the car has changed hands, so we'll have to see if the new owner continues or not.

Yes, I'm looking forward to that.

We know that the new owner inhabits this forum and that he is aware of the car's history so it's entirely possible.

[admiral51]

I still have it at the moment, it has not been delivered yet, still trying to fix a small issue before it goes but 110% sure this thread will be continued

[MikeT]

I believe the car has changed hands, so we'll have to see if the new owner continues or not. Mike, the actuator tests in Diag do need the engine to be started for 15 secs to get a vacuum, not sure about the cycling, the actuator test would be the way to go, but we'll have to wait and see.

Air doser purely electrical on the X7. Only the turbo solenoid uses vacuum, Pete.

[moizeau]

Thanks for that Mike, did they change it on the X7, or are all c5's the same?

[MikeT]

My facelift C5 is the same.

[GiveMeABreak]

Changed on the C5 MK I, MK II and X7 and again on the X7 depending on engine and Euro specification. DW10CTED4 Is fully Euro 5 compliant and due to the need for lower emissions, getting temp up faster, extra power, more weight etc., a lot of mods were made including to the air doser to achieve this.

[admiral51]

We are talking about a 1.6 HDI X7 that is an early 2008 model and does share the same Air Doser from the 1.6 HDI C5 MK2 ( Vin numbers confirmed for parts etc ) that Mike is talking about, so yes they are the same in this situation, they may not be in other C5's.

[admiral51]

Well the cat is out of the bag and yes Mike T is the new owner of what i tongue in cheek referred to as the Devil Car
Already missing it, but that is something i will get over eventually.
However to bring it back on topic.....
Looking back over the thread and the issues raised and fault codes generated the original reason for getting it taken in to be sorted has not so much been forgotten but sidelined.
The original issue was the DPF risk of Blocking and the Service light on, although the car did run well albeit with the odd stutter/kangaroo issue before the DPF issue ( maybe 6 months or more but it was not my daily driver)and the subsequent Turbo Fault ( low pressure ) diagnosis. Then the car developed into a no revs/revs/no revs/revs but no more than 3k with a fair amount of white smoke during this phase.
Having removed and cleaned the Air Doser and its sensors the car then revved freely and drives quite well, but the smaller butterfly valve does not move and return to its normal closed position as freely as it should but better than before getting cleaned.
The DPF is not clogged, it is only 18% full at last check and over 1 litre of Eolys in the tank.
I cannot remember the exact fault code for the Turbo issue, but it had been present for over 20k miles ( 2+ years )and in that time the DPF has been regening as it should and no warning light had come on but had also never been on a Lexia.
My gut feeling is that the main issue is the Air Doser, something that i would have changed but time/cost was against me, but from all the info posted in this thread and elsewhere on this great Forum, the DPF will not regen if there is an issue with the Air Doser.
I have tested the vacuum on the Turbo Actuator and believe it is not faulty, it hits 18 mercury at the Turbo stop and holds the vacuum, i would have liked to change the Turbo vacuum solenoid valve but did not have the right access to do so safely.
Mike has a working Air Doser on his 1.6 hdi C5, it is a straight swap over part, and he also has a new Turbo Actuator and Solenoid valve should he wish to fit them that i did not get round to fitting.
I will be keeping an eye on this and any new threads regarding my old Devil Car as it really does deserve to be kept on the road, i just ran out of time/space and cash.
Mike change that damn Air Doser over if you can, honestly believe that damn DPF service light will go away

And thanks for taking it on, hope everything i have tried and done with all the input from the members here will give you a cracking car running as it should



Edit Mike had a brain fart, put the Air Doser from the X7 into your MK2 C5 and see if it throws a fault up on the MK2 you know your MK2 is running without issues and will negate any insurance issues to test it on the X7 ??

[MikeT]

Merry 25th December to you all. I hope you are enjoying your day whatever you may be doing.

Once this week is over I'll focus on next steps regarding the Devil Car. (There is a certain 'evil, moustached, stereo-typical, cad-look' about this Black X7 so the name's sticking)

Regarding the air doser you're absolutely right Colin. If the faults followed the part swap to my C5, you've likely nailed it.
However, what I'd like to do (before contemplating removing parts from both cars, fitting one to the other and then having to do it all over again in reverse) is to get some supporting diagnostic data as it wasn't available previously. This can also include actuator tests as it's much lighter work for me to consider, ergo less pain-inducing.

And we still haven't ruled out the turbo itself and all the work that may entail. From my first drive, the performance difference is very noticeable though it was just the one drive and it's difficult to pin down exactly. It could be a throttle restriction as much as it could be a variable vane problem, is my best inexperienced guess.

All in all and with the other statutory service work required, it's going to have to go to a garage so might as well make the most of it, saving me any unnecessary pains.
What I keep coming up against is how best to arrange it so it doesn't get out of hand (ie playing parts bingo or surprise extras) and is dealt with in the most efficient (for the garage) and economic (for me) manner possible? I guess I need to have a detailed consultation with the garage first.

[MikeT]

My question is should this butterfly valve be able to move by manual manipulation, it is something that has been bugging me since i cleaned it out.The other valve is moveable and will spring back into place, this one will move and spring back but not all the time and it did take some force to move it unlike the other butterfly valve which had free movement and always returned to its open position.

As you know via PM Colin, the car is in Dory's garage now and they too are suspectiing the doser valve (and maybe the MAF), quoting over £250 for the former part. Yeah, I don't think so.
With the aid of a neighbour, those parts were removed from my C5 engine giving me the opportunity to compare your findings;
By default the EGR throttle butterfly is wide open and the intake heater flap is fully closed. Both move relatively easily by hand and firmly return under positive spring pressure.

The mechanic said he'd do the swap after his lunch so just waiting the result now.