Peugeot 5008 2.0hdi P11AA P0234 strange turbo noise

[wattsey4u2day]

I have a very annoying problem with my car at the moment that it judders during acceleration and wont go past 3k rpm without throwing a P11AA at me. When accelerating on the motorway sometimes, i can get a P0234 overboost code.

The car is on 234,000 miles, at 223,000, it had a new turbo, egr valve, clutch, flywheel, glowplugs. At 228,000 it had the DPF flushed as it was blocked and was believed to be the problem causing the juddering but it has remained.

Trying to cut down on garage diagnosis time, i have replaced the air doser, maf sensor, map sensor, exhaust pressure sensor, intake manifold, checked all turbo pipes for splits or cracks, cleaned out the intake manifold, done a vacuum test on all vacuum lines but nothing is showing fault!

If i unplug the egr valve connector, i wont get any juddering at all but still the p11aa past 3k rpm. Also when the car does an active regen, it wont judder either. I have a couple of youtube videos below if they help





Ay advice is appreciated. I dont have access to Lexia either

[notrix]

Overboost conditions may be caused by faulty wastegate. You might wanna check if the wastegate actuator is operating freely. I had an Audi A4 TDi with this problem and the car went immediately into limp mode when it detected an overboost condition making it almost impossible to drive.

[GiveMeABreak]

@ wattsey4u2day

P11AA: Air Circuit, Maximum Turbo Pressure Exceeded. Incoherence between the position of the turbocharger electrovalve measured and the turbo air pressure measured, detected by the turbo pressure being above 3 bars for 1.5 seconds

Down Grade Modes:

• Deactivation of the request for regeneration of the particle filter from the diagnostic tool
• Cutting of the exhaust heat saver function
• Prohibition of regenerations of the particle emission filter and stopping of those in progress
• Prohibition of the combustion mode that encourages regeneration
• Deactivation of the kick-down control for automatic gearboxes
• Limitation of performance
• Request for emergency closing of the turbo air cooler by-pass unit
• Irreversible deactivation of the vehicle speed limiter (Need to switch the ignition off and then on, in order to make the function available again)
• Irreversible deactivation of the vehicle cruise control (Need to switch the ignition off and then on, in order to make the function available again)
• Deactivation of the tight spot for the cruise control

Customer Issues:

• Noise
• Diesel fuel consumption a bit higher
• Lack of power

Suspect Areas:

• Turbocharging pressure sensor
• Turbocharger
• Turbocharger solenoid valve
• Turbocharger position copy
• Vacuum circuit
• Electrical harnesses

So you need to get this sorted because all the while it is happening the vehicle will stop the particle filter regenerating and soon it will get blocked to the point where it will no longer be able to regenerate. So don't leave it!

The most likely suspect is the turbo solenoid electrovalve - these have a sponge or gauze mesh filter contained in the module somewhere that can become blocked up over time. Take it off, clean the sponge out, dry it and put it back. That may restore the vacuum.

P0234: Boost pressure regulation - Air pressure above the reference value. This is a very similar fault, and points to the same suspects as the previous description.

This is where it is located - the specific electrovalve is number (4)

(4) Proportional electrovalve controlling the variable resistance turbocharger. (5) Cold air circuit electrovalve. (6) Hot air circuit electrovalve. (7) Variable geometry turbocharger.

Here's a close up of the valve:

(1) Proportional electrovalve. "a" Vacuum inlet. "b" Vacuum outlet. "c" breather. "d" 2-way black connector . make: BITRON/PIERBURG. The solenoid valve is a solenoid valve that is normally closed.

These all vary slightly in appearance - there are videos out there on taking these off and cleaning the gauze or sponge filter - depending on type.

If you have a vacuum testing kit you can use that to check pressure - incase you need the part number, it is 9801887680 - which is for the DW10CTED4 engine. Post your VIN up and I can confirm the part number.

[wattsey4u2day]

Sorry I forgot to mention that I changed the electrovalve but still have the same problem, unless I have been unlucky to get another faulty one. I could try swapping Number 5 with Number 4 on the valve side of things. My intake has the hot air side blanked off on both the air union and the air doser. I will see if I can get under the car at some point to visually check the movement of the actuator. Because the turbo is at the back of the engine, its a pain to get to It did occur to me that when I had an injector problem where the car wouldn't start, I had white smoke coming out from the back of the engine. I have also had a report from the garage previously that they have noticed some sooting on the exhaust side of the turbo. Would this have an effect on sensor readings?

I have ordered a fog machine to see if I can find any leaks on the exhaust side of the system this weekend

[wattsey4u2day]

Another thing that has come to mind, what is the breather port for on the solenoid? This is one pipe i havent checked for blockages on. Should i check this?

[GiveMeABreak]

On looking further on this engine - I may have answered my own point about the electrovalve filters - on the DW10CTED4 engine, it seems there is possible a central air and air filter for all the electrovalves, as can be seen in the picture below - item (3):-

(2) Air inlet manifold with integral vacuum reserve. (3) Breather and filter for all the control electrovalves. "c" Outlet towards the proportional electrovalves controlling the double mixer. "d" Pressure drop inlet for the vacuum pump. "e" Outlet to electrovalves : Proportional electrovalve controlling the variable resistance turbocharger Control electrovalve for the EGR heat exchanger by-pass

So on this engine the box shown should contain a sponge that filters all the crap out. When this starts to disintegrate it can cause some weird noises especially when switching the engine off -

It's shown here as number (7) and is part 1618QL. So may be worth checking out the condition of it. So a few things to check - the electrovalve electrical connector, the electrovalve itself as in testing there is sufficient vacuum and then the filter box below:

[wattsey4u2day]

Marc thank you so much for the detailed responses! A great help for sure! I will have a look on Saturday this week and report back

[wattsey4u2day]

I managed to find a spare hour today so I decided to take apart the piping (no 7) and check it over. It was all fine and air was getting through no problem.. I decided whilst I had most of it apart, I would swap the solenoids to see if it would make a difference, then went on a drive on the A road.. What a difference so far! I can pull away and take it right up to 4k rpm and have no code and the boost feels a bit more even than before. Also the juddering seems to have reduced somewhat. The only downside is that I now get a P0488 code come up relating to the EGR valve (which has been causing the juddering). It was a brand new one fitted last year, BUT, the garage had to update the ECU software as the newer EGR only has one electrical plug on it as apposed to two. Its definitely a step forward so far!

[GiveMeABreak]

Ok, good, so you know the solenoid is dodgy - if you swapped the solenoid for the EGR one then the new error is probably relating to that. So try and get a decent solenoid valve to put back and you should be fine. Thanks for the update.

[wattsey4u2day]

Thanks Marc! Il be getting a new one tomorrow from somewhere and will let you know how it goes when replaced. Looking at citroen trouble codes, P0488 refers to the air doser possibly being closed too much (where the faulty solenoid was swapped for). I did notice what sounded like some loud whistling when i had my foot down in 6th before the code came up. Out of interest, what would be more accurate for my car trouble code wise? There seems to be a difference in citroen and peugeot trouble codes, most of the parts on my engine are citroen

[wattsey4u2day]

Well a couple of days have passed and all appears to be much better with the car! The only shudder i get is at just past 2k rpm where it jerks but not as violently as previous, i suspect its the EGR doing something past a certain rev range. Acceleration feels much better and even and not a single code has come up! I have to admit i went to the main stealers to get a new solenoid valve which set me back £62 but atleast i know its compatible and genuine. Thank you so much for the suggestions and help!! Now it should be a breeze getting from Worthing to York this week ha!

[GiveMeABreak]

.....Out of interest, what would be more accurate for my car trouble code wise? There seems to be a difference in citroen and peugeot trouble codes, most of the parts on my engine are citroen

There are common generic codes, but there are also constructor-specific codes. These can vary slightly depending on the engine management ECU fitted to the vehicle (i.e. Siemens, Bosch, Delphi, Johnson Controls, Magneti Marelli etc.) So it's not down to the marque, but the type and implementation version of the injection system.

As they continually tweak the engines to cut emissions and improve efficiency / change components, it requires a variation of the firmware / software of the engine ECU or a different engine ECU altogether. This can introduce a lot of new codes specifically for the version of the engine in the vehicle which is why a lot of generic code readers can only read and interpret basic codes.

Glad all appears well - just keep an eye on it for a while.

[wattsey4u2day]

So a few months have gone by and the P11AA has now gone, but the car still jerks at around 2k RPM upon acceleration. If I unplug the EGR valve, the car will drive like new! The EGR was replaced at 227,000 miles and the car is now on 237,000 miles. Im surprised if it would have clogged up that soon! Would fitting a vented EGR blanking plate on it do any justice to solving the problem? Im thinking of other possibilities aswell that the Catalyser before the DPF would possibly be blocked after such mileage. The DPF was flushed at 230,000 miles and has been regenerating every 200 miles

[GiveMeABreak]

Don't blank or do anything with the EGR - you will end up with more problems down the line.

I can suggest a few further things - there is a technical bulletin that covers issues with a seized / seizing turbo where one or more of codes P0234, P1496 or P1497 are present. Are you getting the engine management light on?

Check the electrovalves are operating correctly.

[wattsey4u2day]

Im not getting any codes or engine light flashing up, its just a jerk at 2000rpm or near enough that is rather noticeable. Before the jerk, you can hear the EGR valve hissing, then after it jerks, the hissing goes and you get full power. I had the turbo replaced along with the EGR and glowplugs at 227,000 miles (aswell as the clutch and flywheel). Both the solenoids are working as they were replaced when I had the P11AA fault.