Please help, the nearby car repair shop cannot successfully handle my car...I am forced to deal with the problem with my car myself.The problem is the following...

- 1. Very strong/thick black smoke at full throttle before 2000 rpm        

2. Difficult acceleration up to 2000 rpm        3. Read with VCDS I have two errors available.

P0101 Air mass meter

P0299 - Boost pressure regulation (underboost)

I've read in many places that this problem is common BUT no one has a solution?

So far I have removed the turbo for inspection,(Turbo service) the turbo is OK.Nozzles Ok The car had a clogged intercooler - I replaced it with a new one, disconnected and removed the EGR  DPF and AdBlue, new air flow meter, compression OK, All turbo hoses are ok (checked with machine) The car continues to have these problems (Loss of power and thick Smoke at low revs)...The car has no smoke at high revs. Please help...  

 

51 minutes ago, Peter Skelto said:

Please help, the nearby car repair shop cannot successfully handle my car...I am forced to deal with the problem with my car myself.The problem is the following...

- 1. Very strong/thick black smoke at full throttle before 2000 rpm        

2. Difficult acceleration up to 2000 rpm        3. Read with VCDS I have two errors available.

P0101 Air mass meter

P0299 - Boost pressure regulation (underboost)

I've read in many places that this problem is common BUT no one has a solution?

So far I have removed the turbo for inspection,(Turbo service) the turbo is OK.Nozzles Ok The car had a clogged intercooler - I replaced it with a new one, disconnected and removed the EGR  DPF and AdBlue, new air flow meter, compression OK, All turbo hoses are ok (checked with machine) The car continues to have these problems (Loss of power and thick Smoke at low revs)...The car has no smoke at high revs. Please help...  

 

Hi what do you mean by removed DPF, adblue,EGR, do you mean deleted, the adblue would not cause any problems like this I would be looking at the live data for the injector functions and have a leak back test done, this is either a dodgy injector [they are five stage piezo units] or a dodgy map.

Steve.

,Software deleted EGR DPF and AdBlue,They were also mechanically removed Dpf. The injectors have been checked at a diesel service center. I doubt it and the next step will be to open and replace the oil lifters, maybe if they don't open the valves all the way...MAYBE

If the injectors are fine, then my money is on faulty re-mapping.

No no, the car behaves the same way (thick black smoke) With original software and remapped, there is no difference in smoking.

Then let me ask another question. Did the engine smoke before the modifications and re-mapping?

Yes.Smoking got worse and worse over time For a long time, the car was driven with a clogged cooler (manifold).The strange thing is that when I turn off the The socket of something, for example - the map sensor, the car goes into emergency mode with reduced power and the smoke disappears 🤯

Edited July 22, 2025Jul 22 by Peter Skelto

So the engine was in a poor state beforehand. In that case let's go back to basics and start with a compression test. Please let us know the results.

The compression of all cylinders is equal and is ok.

Компресията на всички цилиндри е еднаква и е в нормални граници. 

It has also been mechanically checked.

Edited July 22, 2025Jul 22 by Peter Skelto

Those are not pressure readings. I am asking for pressure readings from each cylinder while being cold  cranked by the starter motor with all plugs removed.

As I said above, I mechanically measured the compression and it is OK.                        At high revs, the car accelerates well and there are no smokes.  

If you are not prepared to supply relevent information I can not help further.

do you still have this problem as my car is doing the same and no one knows the fault

1 hour ago, christo098 said:

no one knows the fault

Nobody at all? So you have had the car diagnosed on a VCDS or similar tester and there were no fault codes?

No codes whatsoever said it was injectors had them changed and it still smokes

1 hour ago, christo098 said:

No codes whatsoever said it was injectors had them changed and it still smokes

Hi running way to rich, change the MAP and MAFF sensor as those two will cause over fuelling and smoke especially at idle, also check DPF soot and ash loadings, check air filter and housing for blockage, my bet is its MAP/MAFF related.

Steve.

1 minute ago, Stevey Y said:

Hi running way to rich, change the MAP and MAFF sensor as those two will cause over fuelling and smoke especially at idle, also check DPF soot and ash loadings, check air filter and housing for blockage, my bet is its MAP/MAFF related.

Steve.

I have changed the maf and map sensor and it’s still doing it knocking when reved to 1.5k revs even took it for a drive and still won’t go above 2 and when it gets near it, it starts to jerk

1 hour ago, christo098 said:

No codes whatsoever said it was injectors had them changed and it still smokes

If there were no codes, who or what said it was injectors?

24 minutes ago, christo098 said:

I have changed the maf and map sensor and it’s still doing it knocking when reved to 1.5k revs even took it for a drive and still won’t go above 2 and when it gets near it, it starts to jerk

Hi did you do an adaptation on the MAFF, you did not mention the knocking before as this could be a whole other level as a worn crank or big ends would cause piston shudder which unsettles the oil control rings thus it starts burning its own oil, are you losing oil, just a question you haven't had any emissions equipment deleted?. Only other thing it could be is the PCV valve could have gone try disconnecting it from the intake and see if it still does the smoking.

Steve

36 minutes ago, cliffcoggin said:

If there were no codes, who or what said it was injectors?

Garage said it was injectors

22 minutes ago, Stevey Y said:

Hi did you do an adaptation on the MAFF, you did not mention the knocking before as this could be a whole other level as a worn crank or big ends would cause piston shudder which unsettles the oil control rings thus it starts burning its own oil, are you losing oil, just a question you haven't had any emissions equipment deleted?. Only other thing it could be is the PCV valve could have gone try disconnecting it from the intake and see if it still does the smoking.

Steve

No luck still

1 hour ago, christo098 said:

No luck still

You are not giving us much information Christo. Even the casual mention of knocking was slipped in as an after thought, even though it is significant. Steve asked if you were losing oil, and I ask the same.

I also ask if the car has been re-mapped, has a full service history, and what the mileage is. Without more detail we can not provide sensible advice.

21 minutes ago, cliffcoggin said:

You are not giving us much information Christo. Even the casual mention of knocking was slipped in as an after thought, even though it is significant. Steve asked if you were losing oil, and I ask the same.

I also ask if the car has been re-mapped, has a full service history, and what the mileage is. Without more detail we can not provide sensible advice.

Sorry, I’m not sure if it’s been remapped and has full service history and is currently on 91k miles and it’s not losing oil whatsoever it was a thing that happened overtime slowly worse. Was on the motorway went to switch lanes and then boom suddenly loss of power and glow plug light, I had then come to a stop and restarted the car and then ot drove normal again and then when I got to about 70 same thing limp mode and then over time it slowly got worse more smoke and started getting slower till about a month ago where it started to judder and not go past 2k revs and loads of smoke and won’t even go up the slightest bit of hill an so far I have changed the injectors map and maf sensor but the car starts fine no issues and sounds normal at idle it’s only when reved or driven it starts to happen

6 minutes ago, christo098 said:

Sorry, I’m not sure if it’s been remapped and has full service history and is currently on 91k miles and it’s not losing oil whatsoever it was a thing that happened overtime slowly worse. Was on the motorway went to switch lanes and then boom suddenly loss of power and glow plug light, I had then come to a stop and restarted the car and then ot drove normal again and then when I got to about 70 same thing limp mode and then over time it slowly got worse more smoke and started getting slower till about a month ago where it started to judder and not go past 2k revs and loads of smoke and won’t even go up the slightest bit of hill an so far I have changed the injectors map and maf sensor but the car starts fine no issues and sounds normal at idle it’s only when reved or driven it starts to happen

Hi try any/all of previous suggestions but at that milage I would check the DPF loadings ash/soot as a blocked DPF could cause some of these problems does the car regenerate regularly.

Steve.