RaZtar

Hi everyone,
buckle up, I’ll try explaining this as best I can, I apologize on beforehand in case I am explaining anything poorly.

Car: W212 250CDI 2011 Blueefficiency Avantgarde, i.e OM651.924.

Symptom: Car randomly shuts off while driving, so far only when engine is up at working temp. Some times car can be started right after it shut off, at times it can be started after ~10 minutes.

This weekend for example I drove 50 km one way, car shut of after 27km, started right up and went well the rest of 23km the way there, on the way home it went just fine.

Other days the car refuses to start, always when the car is warm, never been an issue with a cold start. Whilst it refuses to start it has so far paid off waiting 30 - 90 minutes before it finally starts.

All whilst not generating an engine lamp, although there are fault codes, listed below.

Fault Codes read with Autocom (Photo in attachments):

• P0340 - Intake Camshaft position timing (Bank 1)
• P0344 - Camshaft / Crankshaft position sensor row 1; incorrect adaption
• P2A00 - Lambda sensor 1, bank 1 malfunction

Other observations:
The extra water pump by the coolant resourvoir is whining at times.
Prior to this issue the car would go into limp mode of going uphill in speeds above 115 km/h where it would complain of P0252 (Injection Pump fuel metering control A Range/Performance(Cam/Rotor/Injector)

I’ve performed a leak test of the injectors and gotten even values on all injectors.




Parts I’ve changed and done somewhat recently:

• Fuel filter
• Fuel filter holder
• Camshaft sensor (Year ago and didn’t correct first fault code)

Less related stuff but in case I’m naive I’ll list them

• Fuel return line from the injectors
• Charged both batteries
• Handbrake rear both
• Shocks rear
• Changed my oil
• Had Mercedes service gearbox
• Brake pads
• Windshield wipers

I’m going mad trying to troubleshoot this, any help or idea to throw at me would be apprechiated.

Thanks
William

CaliBenzDriver

Excellent job circling all around yout issue. No one could have done this better.

Your diesel likes to quit only when hot, couple sensor codes found.


> The only question I have is:
are these codes CURRENT or STORED??
What happens after you clear faults, come back as STORED ??


> The combination of weird CPS + Lambda faults read like... "oil-in-harness".
Disconnect batteries and check your ECU connectors ... dry vs. oily?


> As far as correlation code...
you have new Cams sensors (both intake/exhaust?)
VVT Gear ok ?
then crankshaft sensor ??


I don't think your fuel pump is involved in this chaos. ECU has enough reasons to quit with severe timing fault.

Arrie

Assuming the fuel pump is mechanically driven by the engine (old diesels had this) the engine stops only when fuel delivery stops. There is no spark to worry about and all possible reasons for losing the spark.

So, is there a fuel valve that is controlled electronically that is “flaky” and randomly closes? Could it have a coil that shorts/fails when engine hot?

Andre Cateb

If I had to guess, your high pressure fuel pump (which is normally driven by your camshaft) is your root cause. If it's about to seize it would explain your camshaft/crankshaft correlation codes, the fuel metering valve code and the sudden stoppage. I think it would be smart to take it out to inspect or at least try to run the car with a real-time scanner connected to monitor how is your rail pressure going behaving.

EDIT: By any chances the issues started or gotten worst after you replaced the fuel filter?