C5 2008 (X7 ?) Turbo Fault

[MikeT]

Thanks Marc.
Colin, given the latest problem which followed you replacing the turbo intake sleeve (making it air tight) it's worth checking the air filter's not clogged.

[admiral51]

Marc firstly the match has not yet been lit but it is still an option , secondly thank you for posting all that information on the fault code

Looking at the list of customer complaints i can confirm the top 2, but the car has never produced excess smoke apart from white smoke once when it did its kangaroo impression 2 weeks ago.
I can also confirm that up until yesterday the speed limiter would work but somedays only for 5 miles or so, sometimes 30 miles and then when coming of the dual carriage way and pulling away it would disappear showing just 3 lines, same thing would happen if paused and you went above set limit.
Yesterday i had the speed limiter working when it chucked its toys out of the pram, took a couple of minutes before i realised the limiter was on but was still doing its kangaroo impression before i paused it and yes i was hitting the set speed limit.
I can def check the air flow meter, air flow to the air filter for obstructions and the air filter by removing the pipe work , that is easy, even i can do that.
The airlock bit i assume is between the Turbo and the sensor ?
Turbocharger position sensor is part number 2 in the diagrams below.
The vacuum issue can be tested as per your diagrams and instructions, which may or may not eliminate the sensor and i maybe borrow the test equipment, have a laptop arriving Friday so i can try and get my lexia/Diagbox up and running.
Variable geometry of the turbocharger jammed in the "minimum turbo" position, would that be the actuator arm described in previous post ?
Faulty Turbocharger = light the match
I will also look at changing the fuel filter as it has that feeling of a blocked fuel filter but cash now needs to be targeted

There is no rush the car is staying where it is for the time being, i just need to get a cheap runaround to get me to work and back by next Monday, have my eyes on a few local sheds.
Once again a real big thank you to all of you from SWMBO and me

[admiral51]

https://www.gov.uk/check-vehicle-recall


can also check if a car has been scheduled to be recalled

Thanks just checked no recall outstanding on that site but will give my local Citroen Stealers a call tomorrow with the Vin number to double check

[admiral51]

I am not giving up yet, but i may just put this thread on hold for the time being, i will work through the list and post updates as i try my best to get this C5 back to health, but with only weekends to tinker i have decided to SORN this one and fingers crossed i will get to the bottom of the problem. I think the car is worth £1200 if running correctly so spending a few quid will be worth it but only in stages as and when i can.
Have been looking at a local French shed as a run around so will probably be posting on the forum for advice as and when it goes wrong if i can get it for the right price

Not a word Mr T

[admiral51]

Have a new daily runaround,still chevrons on the front and a step back in time for me and it has spheres, not good ones but still has them

I have maybe 3 weeks to come to a decision on the C5, spend money on it or send it for scrap.
I am going to order a replacement actuator valve, it will not be an OEM part, think it costs £30 from a UK seller ( Chinese Import ) but having time to think what has been going on i think it maybe worth a punt.
Before i replaced the sleeve insert oil had been leaking form the air feed to the turbo,since it has been replaced albeit for a few days no oil had been leaking.
To my shame how long that sleeve insert had been leaking i honestly do not know,what i do know is that the oil had been leaking above the actuator and dripping down the actuator arm which i believe means it has been dripping onto the diaphram ?
My main issue in replacing the actuator is that it has a locking nut on it to determine the return length of travel of the arm so hence its starting point.
Thinking logically as it is a manually adjusted travel length is there any danger in miss adjustment allowing the turbo vains (sp?) being able to foul ?
Have already checked the air filter, a little dirty but nothing that would suggest it is blocked to allow the severe restriction of air flow that would result in the symptoms i have.
My thoughts keep going back to how long the fault had been present without throwing up a service light and the fact that it had that flat spot, foot down felt like no turbo, lift off for a split second and it gave full beans, cannot remember the exact mileage from the Diagbox session but as it over writes the old data it could have been over 3-4 years, 20+k miles .
I will change the fuel filter, but again this has been changed within the period when the symptoms were logged by Diagbox.

All comments greatly appreciated will take everything on board.

I know the car is not worth much but being a C5 X7 on 100k+ miles it has never had its steering rack changed

Thanks Colin

[admiral51]

Okay so i now have my replacement turbo actuator and i have some questions, like i always do
I am not very tech/mechanically savvy so here goes, you are all going to have fun with this one
As i understand it the actuator can be tweaked to under/over boost the turbo depending on its settings, but having looked at the replacement part i am totally confused.
As i see it the height of the bracket that holds the actuator is determined by the holes for it, and the actuator arm fixes on to a set position set by the location of the turbo actuator connecting rod held in place by a cir clip.
So looking at my replacement it has a stop nut and the arm itself contains a thread that means i can adjust both nut and how far i screw the arm in or out.
If screw the arm itself out it will not line up with the turbo rod, if i turn it down it will also not line up ?
Oh bugger just realised what i think i am missing,apart from a brain
The actuator itself can adjust the starting position of the turbo depending on how it is set up, it can be part open/closed depending how far the arm is shortened/extented, the travel will be the same

Please help me out i am close to being an OAP lol

[xantia_v6]

I don't think you can adjust the boost settings mechanically, as the ECU recalibrates the system so that it gets the amount of boost that it is expecting, and throws a fault if it can't do that.

[MikeT]

With the vacuum hose removed, it's just two 10mm nuts and a circlip, Colin.




Testing faulty vs good actuator




This one demonstrates calibrating the arm setting



And some light reading regarding the solenoid valve at the rear of the engine

http://www.pierburg-service.de/ximages/ ... en_web.pdf
http://www.pierburg-service.de/ximages/ ... en_web.pdf
https://az25411.vo.msecnd.net/pdf/5/pg_ ... en_web.pdf

[admiral51]

Cheers Mike, gonna open a cold can and view

[admiral51]

Thanks Mike have watched them and it now all makes sense, all i need to do is understand the 15-18 mercury thing, and where to scrounge a vacuum meter

[admiral51]

sorry xantia v6 i missed your post, too eager and jumped to last new post.
This is such a big learning curve for me, and from what i believe i have learnt so far yes i can mechanically adjust it but if it is out of ECU values it will throw a fault up and if i my actuator is not holding vacuum it will appear to the ECU as not within values and then record a fault as the ECU cannot get it to do what it wants ???

[admiral51]

Thanks Mike have watched them and it now all makes sense, all i need to do is understand the 15-18 mercury thing, and where to scrounge a vacuum meter

Okay so i had a brain freeze moment, was a long time ago i was at school, figured it out now, it is just a different way to describe PSI/BAR etc
Going to have a look at it over the weekend, anyone up for a bet that i break something else along the way

[MikeT]

I got el-cheapo vacuum pump with gauge if it's any use to you, Colin? Could maybe rendezous somewhere as you're travelling to/from work?

[xantia_v6]

sorry xantia v6 i missed your post, too eager and jumped to last new post.
This is such a big learning curve for me, and from what i believe i have learnt so far yes i can mechanically adjust it but if it is out of ECU values it will throw a fault up and if i my actuator is not holding vacuum it will appear to the ECU as not within values and then record a fault as the ECU cannot get it to do what it wants ???

I was just trying to make the point that the mechanical adjustment can't override the boost level that the ECU decides. A faulty actuator will of course upset everything, as will a vacuum leak .

[admiral51]

Cheers xantia_v6 that makes complete sense

Mike think i have managed to scrounge one but i will keep you in mind

Just need to get the correct vacuum needed to set it at lol