Hi There!

Backstory (my first post)
Long time reader but only owned my W164 320 cdi since 15th of Jan and very much in love with it. Bought it of my brother (and took care of all the services with my trusted mechanic) so the cars history is very well known to me (for over 100k miles) The car has atm 260 000 km on the clock.

Issue:
When I bought the car, I started driving with cold engine, the engine has full power, however after 4 miles the car had no boost, very sluggish and does not rev over 2k rpm. Initially I immediately thought of the Swirl Motor issues and my mechanic did the resistor "fix". However the original issue did not go away.The circle of cold and full power and subsequent limp mode happens after every start and limp mode will come after 2-5 miles. Even if engine is warm, restart, power is there for ~3miles.


Error code
from Delphi system:

"2511 - Exhaus gas recirculation valve position

- intermittent"



Parts changed
so far Intake pipe with MAFS (part 6420908237) and PCV valve&hose (just because).

Edit; Parts changed did not resolve the issue.

Video of the issue
In the link there is live video from Delphi tool which shows how the engine runs "rough" idle (and second vid with accelerator pushed) and how it reacts to pushing the accelerator. New intake pipe and MAFS and reset & relearn were done before filming.

https://imgur.com/a/Qzytpov
https://imgur.com/a/uONRVOh


Me and my mechanic are quite stumped about the issue...

UPDATE AND EDIT 25th of April:

As of now we have still not found out what the issues is.

Parts changed / modifications so far:

- Swirl Flap motor / linkage fix with resistor
- new MAFS & Y Pipe
- new PCV Valve & Hose
- new Exhaust Back Pressure Sensor (after turbo)
- new EGR
- new Fuel Filter
- new Throttle Body

The Throttle Body was changed last because the mechanic was randomly trying out stuff and when he disconnected the throttle body plug the engine run smoothly, when connected again the issue of rougher idle (please see vids above) returned
Right now I feel really at a loss of what to try next... The mechanic told me to look online again, he is not happy to swap more parts randomly

Could somebody explain to me "who or what" comes first in this action reaction cycle? What sensor tells the EGR to actuate? When is the EGR actuated (only when warm or also when engine is cold?)

Any advice is welcome!

 

How old is the fuel filter?

 

I assume from you stating the car has "km" on it that you're not in the US where you could likely get it fixed for free under the AEM warranty?

 

Bunch of more parts were changed but issue still persists, please read the update in the original post

 

Resistor on module, or black tape over CEL is not fix.
You need better mechanic, who can diagnose and repair the car, not just patch it blindly.
Get a good scanner and start DIY troubleshooting. That is always good start.
Liqui Molly is selling diesel intake cleaner for cleaning the flaps.
About $13 at NAPA. in USA, but you choose not to disclosure your location.
Are you still getting EGR code after putting new one?

 

Did you see my post about the warranty? Pretty much everything you listed is covered by the AEM warranty, but again not sure if it's valid in your country.