C5 2.0 hdi 06 Model LOST BOOST ?

[wizaird]

Hi Folks , I would like to attempt to find some answers to this mystery of mine revolving around my Citroen C5

C5 2.0 HDi ( RHR Engine) dcm 3.4 (dw10bted4) Siemen
179000 miles
recent service ; all fluid filters
no EOLYS to my knowledge , maybe someone knows different.

The vehicle has been running great since I purchased it with 169000 miles however in the last few weeks I have a the depollution warning light flash up for unknown reasons during heavy acceleratrion and the warning lamp illuminate.
The car seemed to run fine though despite this ?
Light would go out after a 3 restarts and life continues on..

To accompnay this there was also hesitation evident at roundabouts and junctions every now and then ...I had back off the throttle and depress clutch to avoid stalling and go for it again ...???????

Anyway last week my wife takes it for a good 120 mile round trip and then I take it out and notice there is no BOOST what so ever ?

Car starts fine and runs well ; no warning lights yet no boost ?

It is sluggish up hills and on a falt road I can still get 70 mph all be it taking a while to get there ..then as soon as a hill presents itself the speed drops .

MPG is down and just before this incident I was getting 55 - 60 mpg on the motorway at 70 mph .....it seemed to have increased its performace as well ?

Anyway RAC take a look and give the following readouts (in the order) below syaing the EGR looks to be at fault;

P0490 EGR Valve Stuck
P1461 EGR system Fault
P0489 Intake Air shut off solenoid valve feedback - opening too large.
P1165 Rail Pressure sensor circuit , coherance
P1198 Injectors control; ECU Internal Fault
P0087 Fuel Rail / System Pressure - too low
P0089 Fule Pressure Regulator Performance
P2563 - Turbo 2 solenoid valve exhaust - Blocked This the only one highlighted on the RAC screen ..
P2562 - Turbo Pressure Sensor
P2199 Intake Air Temperature Circuit Range / Performance Problem

Anyway I book it in at a Garage that sepcialise in French vehicles and they say the EGR looks to be blocked.
They remove the apparently faulty EGR Valve and Eurocarparts supply (erronously) an aftermarket part; this is fitted and a guy with Lexia attempts to relearn the ECU for the new aftermarket part;
He said it would not respond to the commands returning 3 watts or soemthing ?

Anyway Eurocarparts will be supplying a geniune manufacturer EGR Valve in the morning and it will be reattempted to ressurect this TURBO.

The EGR VALVE removed had apparently been blocked off ; it had also fell to pieces.

I have asked the the gut who programs the vehicle makes use of the new part costing £180 and not bypass it by wiping it from the ECU.

My question here is .............Would this cause the turbo to stop making boost or are they barking up the wrong tree ?

Maybe someone has dealings with this kind of problem before ......

..I will update this post tommorrow and let you know the outcome as I have spent may hours searching for similar faults and not quite found any threads on it which I thought were bang on..........maybe this thread will save someones heartache and time ......

thanks in advance


Dave ; Leicester

[citroenxm]

Turbo wastegate is vaccum controled by the ecu via the vaccum system and electro valve.

Firstly check the wastegate vaccum pipe .. remove the engine cover and look down the back of the engine.. the wastegate vaccum pipe runs from the right side of the front of the head across the back to the left (drivers side) and down the back to the turbo. Ive bad one of these vaccum pipes colapse and give zero turbo boost.

Operation. Wastegates are normally open. Engine started the vaccum is applied to the wastegate via an electro valve and it closes and therefore give boost pressure into the engine. The ecu monitors boost pressure compared to set pressures over engine range and if it exceeds the set pressures it goes into limp mode... this useually resets with key and engine off and a restart.

Id go with vaccum pipe first on the back... the other thing you can do is take an end off somewhere on the vac pipes and start the engine and feel for a vaccumm..

[wizaird]

Hi Citroenxm , I initially before contacting the garage and after Rac came out to it took a look at the vaccum pipes you mention.
I disconnected the input feed to the solenoid and started the engine up; there was a noticeable vaccuum.
I then stopped the engine and removed the solenoid minus the pipe supplying the wastegate and reconnected the first pipe (inlet) I just checked ; there again after firing her up there was vacuum.
I connected the wastegate pipe and with there being no difference , refitted the solenoid in position and deemed this was working correctly.
I then rang the garage thinking that EGR valve was at fault.
My question regarding this is ; Does the solenoid only engage half heartedly (not giving full vacuum to close the wastegate and produce turbo) if the EGR valve is playing up ?

Thanks for your reply ...much appreciated ...

[citroenxm]

In a word no..

[wizaird]

Latest update as of today 5.30pm.

My car still has no turbo boost despite a new genuine EGR valve being fitted and the ecu being cleared of faults and programmed to relearn the new part ???????????

I am wondering at this point if the solenoid wastegate valve is at fault ...as I have stated before this appears to be generating a vaccum but I am unsure as to what the state of the solenoid valve should be when idling etc .
For example would this solenoid valve be the cause of the problem yet show no fault ? ie ...it isnt engaging the full vaccuum ?

Is there any way to test that the turbo wastegate is operating correctly and engage turbo before embarking on more £ spending ?

can the vaccuum pressure / solenoid be tested manually to ascertain if its working properly or losing vaccuum ?

Thanks in advance for any help given

will keep this post running ...

Dave

[Stickyfinger]

If I may ask....is the "programming" work/fault reading being done via Lexia unit ??

[citroenxm]

Have you looked at the vaccum pipe at the back of the engine as i said above.. you havent said if you have or not...

[dnsey]

It's possible that the wastegate diaphragm or linkage is faulty.
Disconnect the wastegate vacuum hose (engine off), and suck hard then release. If you listen carefully, you should hear a sort of quiet thud as the wastegate operates.
If This is OK, try blowing down the 'source' side of the vacuum system to expose any leaks, most likely a split hose end somewhere
If you have access to Lexia, you can track actual boost against system requested boost while running, which will distinguish actuation problems from ECU / control issues.

[Stickyfinger]

If you have access to Lexia, you can track actual boost against system requested boost while running, which will distinguish actuation problems from ECU / control issues.

Which begs the question, why has the "French Car Specialist" not have a Lexia to check the live data BEFORE they start switching parts for $$$ ??

[citroenxm]

Even I have caught a specialist out too!!

Owner was told turbo was knackered... i spent 5 mins with the car and found a collapsed wastegate vaccum pipe after my lexia showed little turbo boost...

[wizaird]

Hi , the programming was done with LEXIA ?

I haven't spoke to the guy that did it so don't know for sure what else he found while doing it.

The Guy who did it was someone in Loughborough called Sean , he does all the area and is very reputable by all accounts.

As for the pipes ...I think I may have said in an earlier post that I removed them myself from the solenoid actuating valve and ran the engine ...getting a little vacuum pressure from the vacuum pump to the inlet side of the solenoid actuator valve.
Then reconnected it to the solenoid and removed the outlet pipe (wastegate actuator feed) put my finger over the end of the outlet ide and again a little vaccuum could be felt ....then I sucked on the pipe going to the actator and this was hard work ....I couldn't seem to get anything moving and assumed that I couldn't suck hard enough and this would need a Mityvac to test the actator properly.

"To echo a previous poster Citroenxm and clarify the movement and position of the actuator I have the following query ; on my car the actuator arm is fully extended and the wastegate is fully open (no boost) then when you start the engine vaccuum is applied and the actuator arm is drawn in to the actuator pulling the gate closed ? Is that correct ...If so it should be easy to determine if it is working properly or not by watching it when vacuum is applied ?
The reason I ask is so I can determine where the starting point of that rod coming out of the actuator should be.
I can reach down the back and it does seem to be in a fully extended state."


Also seen videos on youtube about freeing off sticky wastedates with MR Muscle Oven cleaner ; any takes on this one ....if this is found to be the fault.

thanks for your input so far ...this bl****y car ain't going to beat me .....The truth will be found ..

appreciate your support Dave

p.s asked the garage to check out the movement of the actuator tommorrow ...I am sure they would have done this intially but anything is possible and they may have overlooked this ...

[citroenxm]

Wastegates are normally open so any turbo pressure goes out the exhaust. When the engine is started vaccum is applied to the wastegate and it closes.. via the electro valve. The ecu diverts vaccum away from the wastegate by switching the electro valve.

Another thing that can happen is over by the brake sevo there are two small vac pipes that come out of the larger vaccum pipe.. the tiny hole can block up and reduce vaccum suction to the electro valve. The commin thing to do is to remove the pipe junction and drill out the hole to increase the bore..

[wizaird]

Hi Citroen xm , will the small vac pipes be relevant on my 2006 model you refer to in your last post on the brake servo....?

I thought on my newer model the vacuum was supplied via the pump on top of the engine and not like the earlier model which was on the brake servo ?

might be wrong as I don't have the car with me ...

thanks Dave

[citroenxm]

Ah possibly.. ive had more to do with the 8v 2.0 hdi but have seen the odd series two. You could be right there.

Id then look at electrovalve controller then.

[wizaird]

Ok thanks for that ... I will update tommorrow with hopefully more positive news ....

thanks Dave