[2013m5]

Banjo bolt.
M10 => 22Nm
M12 => 35Nm

[ivanp]

Thank you, it is a M12 ... i was close ...
However, next time when i need to touch such a bolt ... I wouldn't do it until i have a spare one available and a good set of taps around...
did a short trip 100km, no errors and no air leaks around the exhaust manifold - i have reused the gaskets.

[ivanp]

going crazy - after months the errors are back:
4933 Air system, air to EGR mass flow, plausibility
497D Pressure sensor, plausibility while afterrunning: Exhaust pressure before turbocharger not plausible with ambient pressure

It seems to be related to warmer weather - it started once the temperature were over 10 degrees celsius...
no idea what else to check - egr is new, cooler, intake manifold are clean clean, just a tiny level of dust. backpressure at idle again is unexptectedly low at 200k km ...regenerations seems to be done in time, the pressure sensor before turbocharger is new - only if it is broken as new, i have changed this evening back to the another old one - to see if the behaviour is the same...

[ivanp]

My saga continues ... I have replaced the pressure sensor from intake manifold and also the temp sensor from before throttle valve ... lets see if something will change.
If not - with egr new - it remains just the MAF sensor ...

[bellphegorus]

what Error Codes have it now?

[Node]

Have you tried running air mass system test in ISTA?

[ivanp]

what Error Codes have it now?

Helllo,

The ones which appears from time to time, more often lately 
4933 DDE: Air system, air to EGR mass flow, plausibility
497D Pressure sensor, plausibility while afterrunning: Exhau st pressure before turbocharger not plausible with amb ient pressure

Regeneration is done correctly, backpressure at idle is 6mbars something.
It is manifesting just when driving in the city when staying in lines - the DDE led is on on dashboard and the car cant accelerate as usualu. After a while (2-3 km), DDE led still on - but the cars accelerate just fine. The DDE led becomes off once i start to run at a higher speed - 40-50km/h for 2-3 mins.
It started to manifest more often once the weather became sunny.

I think I have executed that air mass system test in ista but i will try it again.

Thank you  for help!

[ivanp]

Have you tried running air mass system test in ISTA?

Hello,
It seems the air mass system test is not passing. It goes through the steps with all ok until the final evaluation:


Message
Duration: 0 Minutes 12.42 Seconds (12:13:27.929 ... 12:13:40.346 )
The measured values of the assemblies are not OK:
Exhaust gas recirculation
Charging pressure controller/turbocharger. The measured charging pressure was too high.
Check following possible causes of faults:
Exhaust gas recirculation:
EGR cooler sooted.
EGR valve is faulty, has stiff movement or leaks. For pneumatic EGR valve:
Pressure converter faulty.
Pressure converter actuation faulty.
Vacuum supply faulty.
Charging pressure controller/turbocharger:
Engine tuning
Manipulated limit position on turbocharger

If I go through all possible faults:

Check following possible causes of faults:
Exhaust gas recirculation:
EGR cooler sooted - checked, unexpectedly clean
EGR valve is faulty, has stiff movement or leaks - is new
For pneumatic EGR valve: - actually mine is not pneumatic so pressure converter cant be a reason for fault, right?
Pressure converter faulty - not sure how to check it
Pressure converter actuation faulty - not sure how to check ig
Vacuum supply faulty - it keeps the air during a depression test
Charging pressure controller/turbocharger:
Engine tuning - not the case
Manipulated limit position on turbocharger - i dont think that position it can be modified, it seems to be fixed, nothing to adjust visible there.
Strange that during this test - the error is not logged ...
I will recheck pressure converter(new one maybe)/vacuum line which triggers the pressure converter as the one from pressure converter to egr si new.

Other ideas?

Many thanks!

[Node]

It would REALLY HELP if you would share NUMBERS/GRAPHS which are recorded during that test. NOT just final conclusion.

That said IMHO too high boost pressure can cause your air mass plausibility faults. Maybe even pressure faults.

---

If vacuum would be damaged to boost pressure converter, you would have too low boost pressure, so it can be ruled out too.

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Fault can be NOT logged when boost pressure deviation is not that critical.

---

There is a test where turbine gate is moved back and forth (called something like boost pressure converter actuation test). You need to visibly confirm it moves easily with ample of range and does not get stuck.
Or if you can reach it, try to move it by your hands.

[ivanp]

Dear Node, 
Thank you much for your time!

I have attached the pdf of the test and the graph of the temperature difference (no idea if in 2 executions - 2 different results).
Related to turbocharger - i was already tried to move by hand and it is continuously moving. With a bit of resistance but it is the same while i am doing that move up and down.
Indeed based on your logic the issue with pressure too high - should be with the turbo - either the vaiable flaps are getting stuck either with that controller failing from time to time.
I have a second turbo charger refurbished in a professional workshop but i am a bit afraid to replace it as usually the refurbished are not the same quality as the OEM one in the car (only if the one mounted now is failing ...).
Is it possible to replace just the controller of the turbo and to give a try?
I will search also for the test which is activating the controller on the turbo to test that point too.

Thank you,
Paul

20240427_121416_Operations_report_VIN7-WK12839.pdf
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