508 1.6 BlueHDi lack of power

[jmaja]

I have owned this car for a year and had a lot of problems. It's been driven almost 200 000 km. The urea tank and timing belt with gears were replaced on warranty last autumn. The timing belt will be replaced again after 60 000 km or two years on warranty.

During winter there was a NOx reduction error code with counting distance to not being able to start, but I reinitialized the SNR-system with Diagbox. After that everything was fine for a few months.

Now there are a lot of error codes, urea light, counting distance, severe lack of power and cruise control not working. Also there is some white dust on top of the engine bay under cover below FAP.

The first error code was P00BC 00 with some lack of power (0-100 km/h 20 s instead of normal 12 s). There was also NOx related error codes. A bit later the engine light turned off and power came back. Then there was also a warning about FAP blocking and later a very severe lack of power. The engine provides power only at low RPM. Above 2500 rpm nothing. Kick-down makes the car to slow down, but at 1000-1500 RPM power is about normal and it can be driven over 100 km/h.

Before the problems started (engine light and lack of power) there were occasions of quite a lot of smoke while idling/parking. I thought this was related to FAP regeneration, but I'm new to FAP so I don't really know. Also there was a quite clear smell of ammonia then.

Now there are the following error codes:
P02ED 00
P00BC 00
P16E8 00
P16EA 00
P20EE 00
P20F6 00
P2A00 00
P2204 00 (twice for some reason)
P2452 64
P2463 00
P246C 00
P2047 00

Last FAP regeneration is 61 km and 10 times average is 294 km. The FAP pressure drop seems rather high, 17 mbar at 816 rpm and 77 mbar at 2500 rpm. It was much lower last autumn (e.g. 36 mbar at 3000 RPM).

One of the problems might be short distances driven. We mostly drive 5-15 km. Very seldom more than that.

Were should I start looking for a problem? EGR? Leak somewhere? I like to do most work myself and I have Diagbox. But I'm new to modern diesel engines with all the pollution control systems.

VF3**************[VIN obfuscated, can be read by forum staff]

[jmaja]

I did some actuator tests in Diagbox. I could hear some noise in the EGR valve test. I also run the EGR circuit test, which run the engine at 1500, 3000 rpm and idle for about 5 min and showed no errors. Air circuit test was very similar, but it ended with an error:
"The test to check the entire air circuit has detected the following fault(s) :
- Leak detected downstream of the air mixer
- EGR valve sealing fault
- Leak detected downstream of the compressor
- Blockage detected downstream of the air flow sensor
- Blockage detected downstream of the compressor
- Air mixer position fault: Negative drift
- Blockage detected downstream of the exhaust manifold
- Leak detected downstream of the exhaust manifold
- turbocharger faulty
- Turbocharger effectiveness fault
- Turbocharger geometry position fault: Positive drift"

I hope my car doesn't have all the faults listed above! What should be checked?

Then I cleared all the faults and reinitialized the deNOx system. All the warning lights went off and the car worked normally for the 50 km test drive. After the drive I checked the faults and found:
P208E 00
P2204 00 (twice again, both having the same data)

So both related to NOx and nothing about the engine itself.

I didn't really fix anything so likely more errors will come later. Maybe one air duct was not 100% properly in place after the service I did a month ago.

What is normal differential pressure for FAP? At what rpm? I now have 150 mbar at 3000 rpm and 316 km since the last regeneration. I was expecting a regeneration to take place during the test drive, but it didn't. What do Short/Long term regeneration capacity % mean?

How close should the measured and reference air flows be to each other? Now I have 350 and 480 mg/stroke at idle and 400/550 mg/stroke at 2200 rpm. Seems quite far from each other. EGR valve position and position instruction 0% and EGR Cyclic ratio -10% at both rpm.

For some reason now the "check" shows more than 2400 km of AdBlue. It was more than 5000 km before the warning lights came on a few weeks ago. I understood that full 17 litres was put when the urea tank was replaced in Autumn. Only about 5000 km have been driven since that so I would expect there to be more than half tank.

[jmaja]

Now about 100 km more has been driven and the car did regeneration 53 km ago. Now FAP pressure drop is 10 mbar at idle and 90 mbar at 3000 rpm.

The same two NOx related error codes are still all there is.

Now measured and reference air flows are almost identical 257/251 mg/stroke at idle with EGR position 13% and 296/299 mg/stroke at 2700 rpm with EGR position 17%. Engine was colder than yesterday.

I guess I'll just wait for some warnings to appear.

[jmaja]

Yesterday the countdown came back. Day before I had just checked the error codes with Diagbox.
P20EE 00
P20F6 00
P2A00 00
had reappeared. Also the car seems to do FAP regeneration very often. The average distance between the last 10 regenerations was just 129 km.

Yesterday first just the urea light appeared with a warning message to top up AdBlue and not being able to start after 2400 km. Then about 30 km later the car did the regeneration and right after that came the engine fault message with engine light and service light. After some time came the warning about not being able to start after 1100 km.

Could someone give some advice what is going on?

[Doo]

May I ask if you use supermarket diesel or high quality diesel? And do you change the oil before recommended service interval or do you wait, and do you use low ash oil?

I have found with my wifes 2007 Citroen C4 1.6hdi, that using good quality oil and changing at 6000 miles or so as well as BP Ultimate diesel, the engine is excellent! When she first got the car, she bought supermarket fuel and every week I had to give the car an Italian tune up (which was fun), but soon it became monotonous so I insisted she try BP Ultimate diesel and the car has been epic since. This was circa 2013. It costs more, but the value repays itself with reliability, no emissions, higher MPG and a smooth quiet engine.

It is around 90,000 miles and averages about 5000 miles a year. Her journeys are mostly short (work & supermarket for food NOT fuel), yet this engine consistently returns excellent fuel milage and at mot test (yearly safety check) the smoke test shows 0 emissions.

I bought a 147,000 mile Citroen Berlingo Multispace e-hdi (8 valve engine) in March. I think it was a taxi... It has 148,000 miles now and it was somewhat sluggish. I put my 3rd full tank of fuel in 2wks ago and the engine is getting faster, cleaner, quieter and starts quicker. I also changed the oil & filters as well as new timing belt & water pump. Before, I would stamp the accelerator and it would reluctantly pull away, but run out of energy at around 2500rpm and would just make a loud diesel engine noise. Now, it positively pulls right through to 4000rpm and isn't slow in getting there. I had to stop putting things on the shelf under the radio as they now end up on the floor such is it's eagerness to accelerate, lol.

I would imagine you may have a partially blocked DPF and the EGR may be partially blocked. Thy can be removed and cleaned, but in the case of the EGR, cleaning doesn't work for long. The DPF can be cleaned, but it is a messy job and takes a bit of faffing around....

[GiveMeABreak]

My advice is to get it to your dealer - each one of those last 3 fault codes concern a Technical Service Bulletin with action required. You may or may not be charged for the work as these are known issues for which the garage can claim a credit for the work - but to do so they must follow a specific guided diagnostic process - so it's a dealer only resolution to be honest as it will require their expert diagnostics, access to their servers and downloading and reconfiguring of the engine ECU - which you can't do.

Those fault codes concern:
P20EE 00 - Engine management ECU downloading. Reinitialisation of the deNOx system fault codes.
P20F6 00 - Concerns Advanced Fault finding and repair with the Dealer Guided Diagnostics Kit.
P2A00 00 - Concerns the tightening of the NOX sensor.

[jmaja]

Now the new codes are
P20E8 00
P2049 00

The latter one seems to be the one that triggered the engine and service lights.

The average FAP regeneration distance has dropped to 114 km.

I guess FAP regeneration and urea problems aren't really related. But there is something weird going on with FAP, since it's regenerating all the time. The average distance has been 250-500 km earlier.

I'd like to learn to do the repairs myself, but maybe I need to take it to the dealer. The problem is they don't really tell in advance will I be charged or not. Nor how much. I would imagine they have already done some of these, since partly the same error codes were there before they changed the urea tank last Autumn.

I don't think we even have "supermarket diesel" here in Finland. I use Neste diesel, which is made by local refinery partly owned by the government. It should be high quality. I have owned the car only for one year and 10 000 km. It had been serviced when I bought it and I did a service for it in June. I used TOTAL QUARTZ INEO FIRST 0W30.

[GiveMeABreak]

These are short circuit and pressure faults related to the UREA injector system and again are known issues - so mention these to the dealer in combination with the others.

[jmaja]

Today first the 1100 km count down and service light turned off. Engine light with "Engine fault, repair needed" and urea light with "2400 km top up AdBlue" were still on. Then I added 4 litres of AdBlue and expected the latter to disappear, but also the engine light turned off. So no warnings now and all I did was the added AdBlue.

Yet another regeneration was done after that. I guess there has been only about 50 km between the last 3-4 regeneration. What is the criteria for starting the regeneration? According to Diagbox there really hasn't been much soot in the FAP (2-7 g), but pressure drop has been around 100 mbar at 3000 rpm.

[GiveMeABreak]

Regeneration requirement is undertaken using lots of data, based on distance travelled, whether previous regeneration requests were completed or interrupted - which changes the strategy for the next regeneration etc., as well as the soot loading and other factors determined by the engine ECU.

If you are still having those fault codes active in Diagbox that you posted above, I would still get it checked out by the dealer to see if any TSBs apply. Pop your VIN up so I can see exactly which variant you have.

The SCR and DPF systems are separate so should not be mixed up. Make sure you read your owners manual regarding the UREA adding procedure and be wary of the quantities to add and the timing for warnings to disappear. The DPF and Eolys additive systems have their own fault codes and requirements, so treat and deal with any warnings separately.

[jmaja]

Joy was very short! Yesterday engine light with "Engine fault, repair needed" came back. We drive just 5-30 km/day and seem to get different warnings every day.

[jmaja]

Pop your VIN up so I can see exactly which variant you have.

I gave VIN in the first message already.

Where are the SCR and DPF systems in my car? I know where the urea tank is and that the pump in on top of the tank. I also I'm quite certain that the DPF filter is vertical in front of the car. However the manual and a video made by PSA shows both SCR and DPF in a combined catalysator/regenerator under the car.

I did have error codes for DPF blocking and pressure difference. Also there was a warning message about that and then I got the lack of power. But these error codes and warning messages have not reappeared since I cleared the error codes two weeks ago.

[GiveMeABreak]

I didn't see the VIN, but have it now.

There can be various setups depending on models. I have both SCR and DPF at the front of the engine, but you have the SCR at the front (in the CAT) and the DPF towards the rear. It doesn't really matter - there principle is the same - the CAT deals with Hydrocarbons, converting these to water, and CO2, then the SCR converts the NOx into water and Nitrogen and finally the DPF removes 99% of the particulate matter.

So, in your case, you will see an injector somewhere on the catalytic converter, which injects the Adblue via a pipe from the rear tank. The Adblue pump is incorporated in the Adblue tank which is sealed. On the 508 in your case the UREA injector fits into the bottom of the Catalytic converter.

[jmaja]

Thanks! So the vertical thing in front of the engine is the catalysator and SCR injector is maybe the one at the bend below catalysator and near the plastic engine bay bottom cover. Just where there was plenty of white powder and still is some. Also there is layer (maybe 5-10 mm thick) frozen stuff on top of the engine bay cover. This frozen stuff looks a bit like dirty snow or slush and is quite light and brittle. Is this likely leaked urea?

Where are the NOx sensors located? Or is there just one? For some reason my Diagbox doesn't seem to show any reasonable values for NOx, just always 0 and 20 PPM. I have 7.82, which doesn't fully support my car. It can't identify engine ECU, but seems to work quite well with EDC17C60 selected as engine type.

[GiveMeABreak]

Yes that whit stuff is crystalised UREA. It means you have a leak - probably in the injector - and that is one of the reasons for the technical service bulletin - to get it correctly tightened and or replaced.

Your vehicle is on the cusp of the changes, so Diagbox 7.** won't work with many newer systems.