Suddenly: No boost and limpmode

[ApexKek]

Hey everyone, me again.
After i physically replaced the entire boostsystem, the little electronically operated vacuum valves for both the turbo and the EGR, cleaned out my intake and EGR, removed the swirlflaps and bridged the connector, installed a new turbo and new vacuum lines, I am, ONCE AGAIN after almost 3 months of no trouble(but low boost around 1.5bar @3000rpm), stuck in limpmode.

I swear this car is really hard on my nerves.

When i start the car it still has boost, up to 1 bar @~3000rpm, which is way too low. I know it should have 1.4-1.5 around 1.8krpm.
Could one of the actuators already be bad? they were expensive as hell and the car builds and holds vacuum at idle at around 30inHg. dont know if that helps.
It builds up the boost very slowly until it reaches its maximum at 3k which is, as i already said, way too late. I don't know if the issue could be electrical aswell.

I'd greatly appreciate any tips you could give me.
attached file is one of the mentioned vacuum valves that operates on voltage as to how much vacuum the turbo/EGR gets

 

[LostKiwi]

You need to read the error codes. If you don't you can guess for ages and just end up throwing parts at it.

 

[ApexKek]

You need to read the error codes. If you don't you can guess for ages and just end up throwing parts at it.

Codes never helped me on this car, it just says low boost or not enough flow from the egr, but not the cause as to why.

 

[Blobcat]

Codes never helped me on this car, it just says low boost or not enough flow from the egr, but not the cause as to why.

What were you reading the codes with?

 

[LostKiwi]

Common causes of low boost:
Leaking hoses (splits are common and hard to see).
Bad turbo.
Holed or split intercooler.
Broken manifold bolt(s).

Less common causes:
Bad sensor.
Blocked exhaust
Blocked inlet tract (air filter/air box).

Limp mode will also cause low boost..

 

[ApexKek]

What were you reading the codes with?

Xentry

Common causes of low boost:
Leaking hoses (splits are common and hard to see).
Bad turbo.
Holed or split intercooler.
Broken manifold bolt(s).

Less common causes:
Bad sensor.
Blocked exhaust
Blocked inlet tract (air filter/air box).

Limp mode will also cause low boost..

Limp mode completely deactivates boost.
Sensors have all been replaced last year.

 

[mioba]

Codes never helped me on this car, it just says low boost or not enough flow from the egr, but not the cause as to why.

Thats what most generic code readers do, a code reader is only as good as the operator back tracking and finding the source of the cause of the code. Thats why not only using a better code reader is important but having a good indy.

How about the actuator, just to throw another part at it

 

[ApexKek]

Thats what most generic code readers do, a code reader is only as good as the operator back tracking and finding the source of the cause of the code. Thats why not only using a better code reader is important but having a good indy.

How about the actuator, just to throw another part at it

Actuator came new with the turbo.

 

[ApexKek]

Guess I'll just scrap the car, not getting anywhere is really frustrating

 

[Botus]

did u check the back pressure sensor?

when broken

Live data at idle 700 rpm (engine hot)
air intake 1017hPa
boost 1010hPa
Exhaust back pressure 4980hPa
charge pressure 27.6%
boost air temp 85 F !!! (29.4 C)
atmospheric pressure 1017hPa
engine speed 1933 l/min
coolant 191 F (88.3 C)
Air mass 392mg/Hub
exhaust gas recirculation positioner 34.2%

when replaced

Live data at idle 699 rpm (engine cold)
air intake 1022hPa
boost 1018Pa
Exhaust back pressure 1022hPa
charge pressure 27.6%
boost air temp 49 F (9.4 C)
atmospheric pressure 1021hPa
engine speed 701 l/min
coolant 69 F (20.5 C)
air mass 430mg/Hub
exhaust gas recirculation positioner 29.4%

10 min job (sits near the EGR to the right of the turbo when you look towards the back of the engine) £48.06 in stock at local merc dealer - would say very well done but they don't stock the washer so a few demerit points. new sensor fitted (with 24 mm deep socket, old washer stuck on the car so good advice to check these might go adrift whilst doing the job,

 

[onefortheroad]

You can even take the sensor out and if the engine revs passed 3k its giving you a clue. ( its a bit loud , mind )

 

[K1AN1]

Have you checked for an air leak?

Sent from my SM-G981B using Tapatalk

 

[ApexKek]

did u check the back pressure sensor?

when broken

Live data at idle 700 rpm (engine hot)
air intake 1017hPa
boost 1010hPa
Exhaust back pressure 4980hPa
charge pressure 27.6%
boost air temp 85 F !!! (29.4 C)
atmospheric pressure 1017hPa
engine speed 1933 l/min
coolant 191 F (88.3 C)
Air mass 392mg/Hub
exhaust gas recirculation positioner 34.2%

when replaced

Live data at idle 699 rpm (engine cold)
air intake 1022hPa
boost 1018Pa
Exhaust back pressure 1022hPa
charge pressure 27.6%
boost air temp 49 F (9.4 C)
atmospheric pressure 1021hPa
engine speed 701 l/min
coolant 69 F (20.5 C)
air mass 430mg/Hub
exhaust gas recirculation positioner 29.4%

10 min job (sits near the EGR to the right of the turbo when you look towards the back of the engine) £48.06 in stock at local merc dealer - would say very well done but they don't stock the washer so a few demerit points. new sensor fitted (with 24 mm deep socket, old washer stuck on the car so good advice to check these might go adrift whilst doing the job,

Thats an OM642 Issue i believe. I have an Om613, attached file is my engine

 

[Botus]

yep, but likely very similar stuff for the engine management ?

 

[ApexKek]

There are no sensors for the exhaust, everything is handled by the MAF

 

[ApexKek]

Pushing this again, boost starts hitting at 3k rpm ,if it doesnt start limping right after starting, but only 1.0 bar(rated at ~1.5bar). Car then goes to limpmode after some time of it running "normally" with the late boost totally randomly.
cruise control also shuts off randomly or doesnt work at all at times.

 

[Botus]

did you ever check live data with it off and then started....

boost at high revs is the symptoms my fathers had, I think both these caused it.
one was the fuse popped on the swirl flap motor (same fuse F44 also powers up the VTG actuator - hence no boost)
a year later, just like everyone else's the "exhaust back pressure sensor" fails (wrong merc terminology), they mean boost pressure sensor, to provide info to the variable geometry turbo (VGT) actuator

 

[ApexKek]

I have the swirl flaps deleted with a resistor and capped off the openings in the manifold.
Boost pressure sensor was also replaced with an OE part.
At this point i should try getting the EGR and Swirl Flap motor coded out.
Sadly got no tuners in my area tho.

 

[Botus]

put a diagnostic scanner on it clear everything, go for a drive 15 mins, redo the scan and give us all the fault codes...

and whilst there take a look a the data as its running (live data) and check out what it says vs the list I gave above to see if anything is startlingly adrift (yes a different car, but a merc tractor is pretty much a merc tractor)

 

[ApexKek]

put a diagnostic scanner on it clear everything, go for a drive 15 mins, redo the scan and give us all the fault codes...

and whilst there take a look a the data as its running (live data) and check out what it says vs the list I gave above to see if anything is startlingly adrift (yes a different car, but a merc tractor is pretty much a merc tractor)

Need special equipment for the diagnostics, obd dongle and 16pin adapter wont even let me read engine codes, only coolant, boost and maf