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Discussion Starter · #1 ·
Hello everyone , hope you will help me with my problem. My 159 1.9 jtdm doesn't pull up and my turbo boost doesn't past 0.8 bar when i press the pedal to end ,and the car is very slowly , i have removed form system egr and dpf off , the dpf filter is still on the car but we have make 3 holes to make exhaust gases to flow in . After i removed for ecu ,egr and dpf because the dpf was blocked ,my car restored the power for 2-3 months but after a while , my car started to loose power and turbo boost . I i drive my car hard for a while , with 3000-3500 rpm all the time , my boost start to restored a bit and from 0.8 bar max goes to 1.3 -1.4 bar and the car start to pull a little bit better . My question is where is the problem turbo or should I remove my dpf , also my car turn on check light sometimes for lack of turbo boost
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Discussion Starter · #3 ·
probably turbo pressure regulator (VNT solenoid), or defective actuator or sticky vanes inside turbo.. Could also be a split vacuum line to/from VNT solenoid
I have changed 3-4 of them , but anything didn't change , I think is not a turbo problem , because Boost start to high up after I drive hard
 

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What have you changed?

You need to see (no way with an OBD diag soft) if actuator on your turbo wastegate is moving. It seems like it is not, if turbo gauge sits only at 0,8 bar.

You have a classic common cause of overboost issue.
And the cure is to check every part on the path of turbo pressure control circuitry: MAP sensor -> VNT solenoid -> vacuum pipes -> turbine's actuator -> vanes (last step is disassembly/rebuild of turbo)
 

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Discussion Starter · #5 ·
What have you changed?

You need to see (no way with an OBD diag soft) if actuator on your turbo wastegate is moving. It seems like it is not, if turbo gauge sits only at 0,8 bar.

You have a classic common cause of overboost issue.
And the cure is to check every part on the path of turbo pressure control circuitry: MAP sensor -> VNT solenoid -> vacuum pipes -> turbine's actuator -> vanes (last step is disassembly/rebuild of turbo)
I understand you , very good bro . but one thing what doesn't make sense to mee , i why if i keep for a while in 3000-3500 rpm , boost after a while keep restored and the car for a 100 km has a better response and pulls better
 

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Alfa 159 1.9 JTDm Sportwagon
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What do you mean by 'my car is running thermostat free'?
 

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Alfa 159 2.0 JTDm Lusso 6sp.
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I think he means it has no stat at all.... Not a good thing as at speed the car will never reach correct operating temp.....running too cool is nearly as bad a running too hot. Surprised he has not got an EML....my 159 threw one when the stat failed open.
 

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Discussion Starter · #15 ·
Have you done and checked what was suggested before?
Your problem won't fix itself, if you just choose to ignore it..

Better take it to a good mechanic who have experience with Opel 1.9 CDTI engines, if Alfas are a rare sight in your region.
Im going to take to a good mechanic today , but it shows up. the code. " P0238"
 

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Alfa 159 2.0 JTDm Lusso 6sp.
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I have removed the thermostat and , i have used all winter without a thermostat and the car didn't pass 50-60 °C all time
That wont do it any good and wont help your fuel consumption either.......get a stat back in there. Doubt it has anything to do with your current issue though.
 

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Alfa 159 1.9 JTDm Sportwagon
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It's strange as when I first got my car it would not go past 3500rpm without the EML coming on. I changed the MAP and boost sensor but no change. The turbo gauge did not respond correctly and plenty of turbo cleaner was passed through the system as it was suggested the turbo vanes were stuck but no change. The temp gauge was shown the classic stuck open as it took ages to heat from cold and never got to 90'C. I then decided to change the thermostat including the temp sender.

After changing the thermostat with temp sender, the problem disappeared. It revs to the red line the turbo gauge worked correctly and the performance came back.
 

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Discussion Starter · #18 ·
It's strange as when I first got my car it would not go past 3500rpm without the EML coming on. I changed the MAP and boost sensor but no change. The turbo gauge did not respond correctly and plenty of turbo cleaner was passed through the system as it was suggested the turbo vanes were stuck but no change. The temp gauge was shown the classic stuck open as it took ages to heat from cold and never got to 90'C. I then decided to change the thermostat including the temp sender.

After changing the thermostat with temp sender, the problem disappeared. It revs to the red line the turbo gauge worked correctly and the performance came back.
Thanks all for your help ❤
 
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