An update to this issue. A few months ago I washed the DPF with a 6% HCL. It seemed to work well and I got a lot of reddish stuff out as smaller and larger grains or just coloured fluid. Before that the DPF burning (while driving or forced with DiagBox) would just fail. Car had something like 225 000 km. With DiagBox 9.68 I was not able to report a new DPF. I read somewhere that it needs version 9.91, but I haven't yet updated. After thorough flushing I let the DPF dry for a couple of days. It seemed to not change after one day (I used a baggage scale to check the weight).
Once put back to car there was a very clear flue gas leak sound and I located it to the urea injector. DiagBox also showed sky high DPF pressures (250-300 mbar) and the car complained about blocked DPF. I thought I had ruined the DPF. I decided to go for drive. It seemed to start a DPF burn almost right away. It failed and car went to limb mode. I continued to drive on the motorway for about 30 km at 80-105 km/h. Once I stopped the flue gas noise was gone and Diagbox showed only 6 mbar at idle and 30 mbar at 2500 rpm. I hadn't seen so low before. I deleted the error codes and since then no problems with DPF. Seems to burn at 400 km or so intervals compared to 100 km before.
However, urea warnings came stronger than before. Hopefully HCL didn't ruin urea catalyst part of the "DPF/SCR". Error codes seem to relate to pressure and urea injector, so I need to check those.
P20E8 00 Pressure of the urea fluid
Urea fluid pressure too low
P2049 00 Control of the urea injector
Short circuit to positive
Replace the urea injector? Can it be easily tested? For some other I found 12 ohm resistance between the pins. Can it be tested with 12 V.
But first I need to get the car starting again (see another thread)!
508 1.6 BlueHDi lack of power
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jmaja
- Posts: 26
- Joined: 09 Jul 2021, 22:29
Re: 508 1.6 BlueHDi lack of power
I took the urea injector off the car. It had only 2 ohm resistance between the two pins. It took 5 A 7.5 V from my lab power supply and made no sound. Seems to be faulty. Is there supposed to be a gasket between the injector and the exhaust pipe? There was none and the injector was quite loose. If yes, is it supplied with the injector?
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jmaja
- Posts: 26
- Joined: 09 Jul 2021, 22:29
Re: 508 1.6 BlueHDi lack of power
Strangely the resistance was about 35 ohm when the injector had been at home for a week. But the new one (50 € Maxgear) had about 13 ohm and clicked well below 12 V and was airtight before click and not after that. The new one had a seal fixed to it and was a tight fit to exhaust system.
Unfortunately changing the injector was not enough to get the Adblue working again. After a few km drive first came engine light and soon after urea and service lights. Diagbox showed only one error code P20E8 00. So there is likely something wrong with the urea tank, which was replaced 4 years and a bit over 40 000 km ago.
Unfortunately changing the injector was not enough to get the Adblue working again. After a few km drive first came engine light and soon after urea and service lights. Diagbox showed only one error code P20E8 00. So there is likely something wrong with the urea tank, which was replaced 4 years and a bit over 40 000 km ago.