Slow Turbo Spool on 2L TDI BKD A3 8P '04

fakitol

Active member
Joined
Jan 10, 2015
Location
Lithuania
TDI
Audi A3, 2005, 2L 16V
Hello,
after injector seal replacement, seat cleaning and adjustment my A3 has lost power from low end rpm. Also fuel economy went down...
Torsion is at 0.0;
Injection qty at idle when engine is warm 4.8-5.2mg/str;
Cyl dev. -0.3 to 0.3;
Fuel consumption on idle 0.4L/h

Going constant 2k rpm and 6th gear with full throttle open, rpm builds up very slowly... Uphill it stuck at those 2k rpm

I've attached log from 4th gear to ~redline.

https://drive.google.com/file/d/1SA_owibunZvm_rAumUQmF_Da02dz1Rct/view?usp=sharing
3rd gear with 3,8,11 groups:
https://drive.google.com/file/d/106xjf1o6EO7zYz8QyCVk0Uve05IBLyuW/view?usp=sharing
Thank you for your help :(
 
Last edited:

mextdi

Veteran Member
Joined
Dec 16, 2013
Location
San Antonio, TX
TDI
2006 Jetta TDI 1.9, 2012 Passat TDI SE DSG, Previous 2014 Beetle TDi, 2012 Golf TDi DSG
Just because torsion says it is at 0.0, it could be past 5 degrees either way. The sensor doesn't read past five degrees so if it is past that or retarded past that it will tell you it is at 0.0

Double check and adjust accordingly.
 

fakitol

Active member
Joined
Jan 10, 2015
Location
Lithuania
TDI
Audi A3, 2005, 2L 16V
Just because torsion says it is at 0.0, it could be past 5 degrees either way. The sensor doesn't read past five degrees so if it is past that or retarded past that it will tell you it is at 0.0

Double check and adjust accordingly.
So from the log you see that this could be the torsion problem?

But the value changes when I press the accelerator pedal. So it is still could be out?
 
Last edited:

mextdi

Veteran Member
Joined
Dec 16, 2013
Location
San Antonio, TX
TDI
2006 Jetta TDI 1.9, 2012 Passat TDI SE DSG, Previous 2014 Beetle TDi, 2012 Golf TDi DSG
I would still double check that when you move the camshaft pulley a little forward or backward it is telling you more than or less than 0.0

I have tried setting mine to 0.0 and it was VERY difficult, just mark where your pulley is right now so when you move it, you are able to go back to where you began. I highly doubt you are at 0.0

You also want to check your vacuum connections, especially the ones to the N75 valve,
those are always disconnected when doing major service and sometimes they are connected back incorrectly or not connected back at all. Those will cause MAJOR turbo issues if not plugged in or plugged in incorrectly.
 

fakitol

Active member
Joined
Jan 10, 2015
Location
Lithuania
TDI
Audi A3, 2005, 2L 16V
I would still double check that when you move the camshaft pulley a little forward or backward it is telling you more than or less than 0.0

I have tried setting mine to 0.0 and it was VERY difficult, just mark where your pulley is right now so when you move it, you are able to go back to where you began. I highly doubt you are at 0.0

You also want to check your vacuum connections, especially the ones to the N75 valve,
those are always disconnected when doing major service and sometimes they are connected back incorrectly or not connected back at all. Those will cause MAJOR turbo issues if not plugged in or plugged in incorrectly.
N75 works, because with disconnected vacuum from turbo actuator the car is dumb and N75 output test moves vnt arm freely.

To remove valve cover it isn't necessary to disconnect vacuum connections, just the part with maf sensor.

Yes, setting to 0.0 is very complicated. 1mm and you can be out to +-4deg.
 

fakitol

Active member
Joined
Jan 10, 2015
Location
Lithuania
TDI
Audi A3, 2005, 2L 16V
Ok,
I've have tried to adjust torsion, at is 0.0. If it is way off car doesn't start.

N75 actuator keeps pressure. -20hg is from vacuum solenoid valve with "6"(N75)


 
Last edited:

mextdi

Veteran Member
Joined
Dec 16, 2013
Location
San Antonio, TX
TDI
2006 Jetta TDI 1.9, 2012 Passat TDI SE DSG, Previous 2014 Beetle TDi, 2012 Golf TDi DSG
From your logs, it is obvious that the turbo is spooling up very slowly. Looking at specified vs actual numbers this is showing that. A slow spooling turbo is caused by a few things. Basically you want to check for intake or exhaust leaks, proper operation of your MAF, intercooler and intake not clogged. What does your EGR valve look like? A clogged EGR can stop the turbo spooling correctly. You WILL find lots of black gunk inside your intake and we all have it, but a lot of it on the EGR can limit its function. Try removing it and cleaning it and report back.
 

fakitol

Active member
Joined
Jan 10, 2015
Location
Lithuania
TDI
Audi A3, 2005, 2L 16V
From your logs, it is obvious that the turbo is spooling up very slowly. Looking at specified vs actual numbers this is showing that. A slow spooling turbo is caused by a few things. Basically you want to check for intake or exhaust leaks, proper operation of your MAF, intercooler and intake not clogged. What does your EGR valve look like? A clogged EGR can stop the turbo spooling correctly. You WILL find lots of black gunk inside your intake and we all have it, but a lot of it on the EGR can limit its function. Try removing it and cleaning it and report back.
Yes spool is slow, and before it was spooling to 1,5 bar actual. It was everything okey until injector o-rings replacement.

Couple days ago I've tried different MAF and it didn't help. Also tried to swap solenoid valve block - also no diffence in spool.

EGR is in quite good shape. Doesn't look that bad like in photos from google :D.
 
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