2005 ML 270cdi cut out and warm start issue

[StephenGib]

Hello. My 2005 ML 270 cdi has been playing up and yesterday was recovered after a non start.

It all Started Last Sunday driving along after a few minutes the EPS light was showing on the dash.. but it drove fine then after a minute went off.

Car starts first time from cold… runs and idles perfect… but then on Tuesday after putting into drive and pulling off it stalled.. but restarted first time and drove another few minutes then stalled again…. But restarted and was fine after that….

Then fast forward to yesterday it fired up from cold and idled perfectly, let it warm up and drove a few miles no issues, smooth and responsive…. Then we stopped for some shopping and then would not start. Just spun over and over… it went to go once but wouldn’t fire.. I couldn’t see any fuel coming through the little clear inline fuel filter at the rear of the engine.

Car was recovered and will be dropped off to Mercedes on Monday. Obviously when the recovery guy turned up 20 minutes later it started but he took the car anyway.

Car has done 126,000 kms ( I am in Gibraltar )

Anyone else had these symptoms before?

 

[mersum1es]

crank sensor...

 

[StephenGib]

Thank you. Would that cause it to occasionally stall when cold and the EPC light to flash up?

 

[mersum1es]

Engine will be shut down if crank sensor data is not received. So yes. I would believe EPC needs rpm info too. Usually sensor problems start when warm, escalating to cold. But fault codes will tell for 100%.

 

[Steve@Avantgarde]

crank sensor...

Rarely fail on these engines.

I'd say it's either got an injector leaking off too much or air entering the fuel system through the seals on the plastic pipes to the HPP and injector rail/filter.

That is very common and mostly the cause of your fault.

The EPC light comes on due to a loss of fuel pressure (will come on if it drops below 180 bar and engine will cut out at below160 bar)

 

[StephenGib]

The car is being taken in to Mercedes today. I will feedback once I hear from them. If it’s just a crank sensor or an injector seal kit I’ll be happy:

All the fuel lines were replaced by Mercedes in 2021 cost £1021 !!

 

[Steve@Avantgarde]

The car is being taken in to Mercedes today. I will feedback once I hear from them. If it’s just a crank sensor or an injector seal kit I’ll be happy:

All the fuel lines were replaced by Mercedes in 2021 cost £1021 !!

Blimey, Gib is full of money isnt it...

Injector the most likely cause then.

 

[StephenGib]

Mercedes called this morning. Plugged it in and there are codes for both cam and crank sensor failure. They have reset codes, run it for a couple of hours and it’s fine, starts and runs and won’t cut or fail to start again…. They are checking one more thing then i think it’ll be new sensors. Annoying it won’t do it while they have it.

 

[StephenGib]

And FYI there is good fuel pressure, no air in the system and injectors are all working fine.

 

[ajlsl600]

Iffy crank sensor does not always stop running motor but will likely prevent a restart. And can work fine cold and play up hot or other way around. Had fair amount of aggro with these on Hitachi excavators 670,870.

 

[StephenGib]

New sensors being fitted on Monday. They can’t see anything else it could be and the fact there were codes stored for cam and crank sensors suggests they could be the issue here…

 

[ajlsl600]

Yup but I bet it Ain't both!!