Checked everthing I can and still have boost fault

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dawsy 22
Posts: 72
Joined: 09 Aug 2012, 21:27

Checked everthing I can and still have boost fault

Post by dawsy 22 » 23 Apr 2013, 15:20

Hi again all my 2.2 C5 with this annoying boost problem has got the better of me I have checked all pipes from the turbo through the inter cooler for leaks and have found none I have blanked off the EGR pipe ,had a look at the diaphragm on the turbo but not realey sure how to check its operation as its almost impossible to access the pipe work.the visual inspection all looked ok there seemed to be bo rust around the pin that goes into the turbo and it looked shiny as if it had been moving freely whilst I was doing this I thought I would check the MAF sensor which looked a bit dirty the car ran better without it being connected,MAF now cleaned car runs a bit better now but it still has this annoying lack of boost syndrome,still MOT is due next month so if that dont kill it i will have to wait for the cambelt to snap before I am rid of this god forsaken car

taffy
Posts: 1003
Joined: 08 Oct 2012, 00:35

Re: Checked everthing I can and still have boost fault

Post by taffy » 23 Apr 2013, 18:12

im still having this problem on my 2.0 hdi xantia...ive put a guauge accross boost vacum and i think its a problem with the ecu sending correct boost readings...im looking at boost sender unit now next to intercooler..sender is about 30 off ebay..like u ive checked everything else

taffy
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Joined: 08 Oct 2012, 00:35

Re: Checked everthing I can and still have boost fault

Post by taffy » 23 Apr 2013, 18:28

and its intermittent but ive never had boost at 1500 like i should it will allways kick in at 3000 and sometimes before but a minimum off 2000

taffy
Posts: 1003
Joined: 08 Oct 2012, 00:35

Re: Checked everthing I can and still have boost fault

Post by taffy » 23 Apr 2013, 18:34

one other thing i was gona try was hook up the two solonoids other way round as they both act differntly...but not sure...the egr on m,ine would close the wastegate till 1500 then let go as my turbo solonoid its kept closed at 0.7 bar and very gradually released untill 0.4 bar max...maybe they are wrong?

dawsy 22
Posts: 72
Joined: 09 Aug 2012, 21:27

Re: Checked everthing I can and still have boost fault

Post by dawsy 22 » 23 Apr 2013, 18:41

Its so frustrating the car has never failed to start and has always got me to where i want to get to,but with this limited boost things can get a bit tricky when doing overtakes,swmbo gave me a rollocking last week when i was attempting a overtake on the A419 by the white hart junction hit the slope and the car stopped pulling and left me at the mercy of the 40 footer beside me (not nice}I just dont want to and cant afford to keep chucking money at it it has other faults that need fixing but until i can sort this one I cant justify doing the other bits and every month another little niggle pops up but unless they are cheap fixes they get added to my to do list

citroenxm
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x 27

Re: Checked everthing I can and still have boost fault

Post by citroenxm » 23 Apr 2013, 19:14

Taffy..

Turbo problem WILL be the Solinoid on the right that controls the waste gate...

Heres the operation. Firstly, check the vaccuum pump. The Wastegate closes WITH a vaccuum, and is normally OPEN. So, when the engine is started the vaccuum is directed via the solinoid to the wastegate and closes it for the boost to be directed INTO the engine. Then while driving etc, the ECU watch's the turbo boost, which has a set figure MA boost in the settings, Which cant be changed with a Lexia, when the boost reaches the max boost setting it switch's the vaccuum to exhaust in the solinoid, this then opens the wastegate and prevents over boost. From the sound of it the wastgate is staying open, meaning the solinoid is stuck on exhaust. The EGR solinoid does the same job in the same way IF WORKING CORRECTLY....

Id be pretty certain that this is the cause of your turbo problem..

Dawsy22... Id be inclined to say this is what your problem is too.. The 2.2 hdi turbo vanes need the vacuum to "Wake" the turbo up.
The solinoid vavles are located up the back, to the left of the Servo unit..

dawsy 22
Posts: 72
Joined: 09 Aug 2012, 21:27

Re: Checked everthing I can and still have boost fault

Post by dawsy 22 » 23 Apr 2013, 21:34

citroenxm wrote:Dawsy22... Id be inclined to say this is what your problem is too.. The 2.2 hdi turbo vanes need the vacuum to "Wake" the turbo up.
The solinoid vavles are located up the back, to the left of the Servo unit..
If this was the case if I remove the pipe from the electro valve i should get my boost back i have tried this and it makes no difference to the sound or performance of the turbo out of interest which colour electrical connector goes to the electrovalve for the turbo and the egr

citroenxm
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Joined: 31 Dec 2004, 00:10
x 27

Re: Checked everthing I can and still have boost fault

Post by citroenxm » 23 Apr 2013, 21:47

No.. it needs the vaccumm applied to work.. disconnecting the vaccuum pipe will stop the Turbo and it won't work. .

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waynedance
Posts: 973
Joined: 29 May 2011, 22:56
x 8

Re: Checked everthing I can and still have boost fault

Post by waynedance » 23 Apr 2013, 22:22

Can you get under the car to see what is happening to the actuator on the turbo?

I may be wrong but on tickover the vacuum should pull out the rod on the turbo and let it in when engine speed increases.

dawsy 22
Posts: 72
Joined: 09 Aug 2012, 21:27

Re: Checked everthing I can and still have boost fault

Post by dawsy 22 » 24 Apr 2013, 06:44

waynedance wrote:Can you get under the car to see what is happening to the actuator on the turbo?

I may be wrong but on tickover the vacuum should pull out the rod on the turbo and let it in when engine speed increases.
I think mine must be stuck in between the two positions as it has no bottom end grunt,

taffy
Posts: 1003
Joined: 08 Oct 2012, 00:35

Re: Checked everthing I can and still have boost fault

Post by taffy » 24 Apr 2013, 09:49

citroenxm wrote:Taffy..

Turbo problem WILL be the Solinoid on the right that controls the waste gate...

Heres the operation. Firstly, check the vaccuum pump. The Wastegate closes WITH a vaccuum, and is normally OPEN. So, when the engine is started the vaccuum is directed via the solinoid to the wastegate and closes it for the boost to be directed INTO the engine. Then while driving etc, the ECU watch's the turbo boost, which has a set figure MA boost in the settings, Which cant be changed with a Lexia, when the boost reaches the max boost setting it switch's the vaccuum to exhaust in the solinoid, this then opens the wastegate and prevents over boost. From the sound of it the wastgate is staying open, meaning the solinoid is stuck on exhaust. The EGR solinoid does the same job in the same way IF WORKING CORRECTLY....

Id be pretty certain that this is the cause of your turbo problem..

Dawsy22... Id be inclined to say this is what your problem is too.. The 2.2 hdi tur

bo vanes need the vacuum to "Wake" the turbo up.
The solinoid vavles are located up the back, to the left of the Servo unit..
Wat about The actuator maybe being week?
Thanks for advice
And also shall I try swaping The solonoids around

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waynedance
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x 8

Re: Checked everthing I can and still have boost fault

Post by waynedance » 24 Apr 2013, 18:47

There are treatments that claim to free off sticking turbo vains, Forte lubricants do one. I have over the years used Forte diesel treatment which did get rid of a slight power loss when pulling off and recently Forte oil flush which has taken my mpg from mid 30s to now so far 43mpg.

Good luck with your fix.

taffy
Posts: 1003
Joined: 08 Oct 2012, 00:35

Re: Checked everthing I can and still have boost fault

Post by taffy » 25 Apr 2013, 14:21

Well thought id have a tinker today and I've made progress!
First I checked The vac pipe from pump thouroly and found a split rite by The pump...so went to cut and rejoin and broke The plastic pipe from The pump! So had no choice I removed The plastic piece and conected The vac pipe straight to The metal pipe...then I thought diconect The egr solinoid completly and jus hook up The vac straight to The turbo solinoid...jus went out for a test and my god its sooo nearly there now! She was flying! On The vac before I was getting round 10-11 psi vac now I'm upto 19-20psi! Its deffo shuttin wastegate now but I'm still not gettin 1500 boost...lot closer thou 1700 was lowest!
Thank god!

taffy
Posts: 1003
Joined: 08 Oct 2012, 00:35

Re: Checked everthing I can and still have boost fault

Post by taffy » 25 Apr 2013, 14:24

Get rid if egr its no good especially high milage...jus hav it ready to reconnect for The mot

taffy
Posts: 1003
Joined: 08 Oct 2012, 00:35

Re: Checked everthing I can and still have boost fault

Post by taffy » 25 Apr 2013, 14:50

If The egr don't throw up a fault on The c5 it might work