Vacuum and limp mode


New Member
Oct 28, 2010

I've been having an on-going problem with my E320 cdi W210 (2002) model.

Original problem was no boost, hard acceleration or kickdown car ran ok until I switched it off then limp home mode.
Got codes read , read Maf and EGR.
Got new maf from merc and cleaned out egr valve which was caked in soot, Also the transducer on the egr side was blocked and the vacuum pipe going to the egr was also blocked. Cleaned everything out ( sucked on vacuum pipe to egr and the little plunger was moving in and out freely ), I could also press the valve spring in and out with ease, re-assembled everything took car for a spin still problem persists (limp mode).
Managed to get a replacement transducer from a local breaker fitted part and immediately got full rev range thought problem was gone but under hard acceleration I couldn't hear any boost from turbo.
I swapped the transducer from the turbo side to the egr but still the same problem full rev range but no turbo boost. Disconnected the vacuum pipe from turbo transducer to the turbo, sucked on pipe and waste-gate pivot moving freely, connected back up still full rev range but no boost.
With engine running I removed the small grey vacuum pipe at the turbo side couldn't feel any suction, connected back up and tried the same at the egr side and the same could't feel any suction.
I've also noticed the engine sounds louder but smooth although not as smooth normal.
Also the large black pipe that runs from the servo to the front of the engine. when you remove the pipe from the front of the engine you can feel suction from the engine side. ( this pipe can be slid off quite easy without pressing the release clips is this normal ).

Does the ecu have any control off the vacuum thinking ecu has shut down turbo as this morning I tried to boot it to see if I was getting any boost still none but it did throw out alot of black smoke when accelerating hard and epc light came on. I stopped switched car off waited a minute re-started no problem have stopped and started a few times varied acceleration but epc light hasn't came back on. Im waiting for my mate to get it back on the computer to read faults but trying to get more insight into problem as he can't get me booked in until the weekend.
Is it simple to do the shunt to disable the egr and if so does anyone know in simple terms how its done and if you need any components to do it where can these be purchased.


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