[skyrimzz]

hello guys we have been strugling with this car for last few days..dtc is 244c00 charking pressure control,control deviation,charging pressure too low...we dont have any leaks,intake mainfold changed,all the pipies are great,it is tested with pressure and there is no leak..new turbine is also and car cant make more then 1.7 bar ..when it need 2.6 it gives only 1.7..there is always big difference in need of boost.on lower revs it need 1.7 and it gives 1.3..tried with different map sensor same result.we made dpf off,swirs,egr (dpf is drilled) and still the same..when we return to ori map still nothing.we even blocked egr  but the same thing is going on..on other forum some member resolved it with disconecting exaust sensor on mainfold but it didnt work for us..nobody has any idea anymore so im open to new ideas?thanks in advance



Solved...this car has another catalyst converter behind dpf and that one was clogged..ista d mass air test car passed and all pressures was good..but car measures difference on dpf and difference was ok so exhaust system passed test without problems.if u do dpf off on this car then u must drill that catalyst converter also cause it is possible that u will have problems like we had.

[marcdts]

I had this issue on my car , randomly appears for 1 seconds and after dissapears , car runing fine

[skyrimzz]

I had this issue on my car , randomly appears for 1 seconds and after dissapears , car runing fine

did u fix your car?this car doesnt go well..it does on easy throtle and on slow speeds..when it needs more boost it stop delivering more then 1.7 bar..

[Node]

But you already replaced/broke half a car. Why not replace the rest???

[skyrimzz]

But you already replaced/broke half a car. Why not replace the rest???

good onethanks for smart and helpfull answer

[Node]

But that else can you expect??? When question is like "I tested this and that and here is the data" then you can draw some conclusions from it and offer some insights. And it's fun to solve the puzzle.

Your question is like "I broke this, replaced this and that" so the ONLY possible answer is replace what you have not yet replaced! There is no puzzle here hence no fun to even start trying.

P.S. SERIOUS question on this topic would be "I did air mass test using ISTA and here are the results (curves and other data)".

Or at the VERY LEAST:
1. I used diagnostic equipment and checked that charge air pressure actuator is NOT stuck and moving properly.
2. Either I verified that boost pressure sensor is giving CORRECT readings or I verified that calculated and actual air masses are more or less the same.
3. Plenty of other things to test/measure while the air mass test in ISTA does MOST OF THAT in one step.

[skyrimzz]

But that else can you expect??? When question is like "I tested this and that and here is the data" then you can draw some conclusions from it and offer some insights. And it's fun to solve the puzzle.

Your question is like "I broke this, replaced this and that" so the ONLY possible answer is replace what you have not yet replaced! There is no puzzle here hence no fun to even start trying.

P.S. SERIOUS question on this topic would be "I did air mass test using ISTA and here are the results (curves and other data)".

Or at the VERY LEAST:
1. I used diagnostic equipment and checked that charge air pressure actuator is NOT stuck and moving properly.
2. Either I verified that boost pressure sensor is giving CORRECT readings or I verified that calculated and actual air masses are more or less the same.
3. Plenty of other things to test/measure while the air mass test in ISTA does MOST OF THAT in one step.

u dont have to be scientist to watch the readings and explain them..i have other bmw with n47 engine and i watch all the readings from that car..maf,turbo is new,it shows same boost as old one,so it isnt turbo..i have tried everything and that is why i asked if there is something that i missed..and if u have read carefully i didnt broke the car,care came broken to us..and if u didnt want to help u didnt had to write.i tried to help every person who asked me for something,not tried to play smart..

[Node]

Of course you don't have to be scientist. But in my experience maybe 1% of mechanics AT MOST can really SEE what the readings TELL, not just look at the numbers! IF your pressure is too low, but ALL other numbers are ideal, my first suspect would be the boost pressure sensor itself. It was NOT in the list of your parts cannon. If the boost pressure is REALLY too low, then ONE OR MORE OTHER numbers WILL ALSO be skewed. And ONLY THEN knowing which ones are also skewed one can narrow down what could be wrong. Hence I wrote what I wrote. Without ANY data I CAN suggest you replace other parts but I CAN'T suggest which ones exactly.

[skyrimzz]

Of course you don't have to be scientist. But in my experience maybe 1% of mechanics AT MOST can really SEE what the readings TELL, not just look at the numbers! IF your pressure is too low, but ALL other numbers are ideal, my first suspect would be the boost pressure sensor itself. It was NOT in the list of your parts cannon. If the boost pressure is REALLY too low, then ONE OR MORE OTHER numbers WILL ALSO be skewed. And ONLY THEN knowing which ones are also skewed one can narrow down what could be wrong. Hence I wrote what I wrote. Without ANY data I CAN suggest you replace other parts but I CAN'T suggest which ones exactly.

that is the weird part..and that is the reason i asked for help..when i watch values,i look at air mass,boost pressure,back pressure,pressure at exuast on mainfold,temperatures and we drive ,sometimes more then 10 kilometers to see what is wrong..that is why i test it with other car..all values look the same..there was some weird thing with one guy,he had the same problems and he just plug out exaust sensor (it reads boost on mainfold exaust ) and car went well,soon as he plug it in car doesnt..i had investigate how does he works and he is connected with egr flow and as i have noticed with vgt..this is very hard problem,i do understand u that lot of people use diagnostic for reading errors..we dont..something in this car is making problems with boost and i think that is more software related..but thanks for answer..when i resolve it i will post

[Node]

So RECORD graphs of data in ISTA expert mode and provide us with those graphs! If you can provide such graphs for similar operating conditions from known good engine then even better!

Because possibilities are TOO MANY to list. For example if DDE sees too high charge air temperature, it WILL INTENTIONALY DECREASE charge pressure. So data WOULD SHOW the temperature, commanded variable turbo setting and so on. There are OTHER situations when DDE will INTENTIONALLY decrease said pressure. Now without ANY data we DON'T EVEN KNOW whether we have issue when DDE ASKS for high turbo pressure but does not get it (or maybe just THINKS it does not get it), or it COMMANDS said pressure to be low to begin with!!!

Help us to help you by going step by step along with diagnosis. Otherwise I don't think anyone on this forum has this new BMW diagnostic device https://cartechnology.co.uk/showthread.p...#pid561159