forfoxsake

Just recently my c220 cdi has started to cut out for a couple of seconds and then pick up again. it doesn't happen at any particular time, temp or speed and doesn't show any malfunction at all, so was wondering if anyone has had the same problem and might know of a fix or some idea as to what to look at, before succoming to taking it to a service agent. Thanks in advance.

Carsy

With no other symptoms you have a blank page to start your diagnosis.

Maybe it is going in & out of limp mode.

Here is Ausmbtechs diagnosis of some problems. :-

"Does it always have low power or is it fine then looses power after driving for a while?

Common issues are jammed turbo vanes, air flow sensors, EGR valve blocked, boost pressure sensor faults or vacuum leak to the turbo control valve or damaged intake manifold flaps.

Only having the fault code for low boost pressure and if there is never full power then I'd suspect the boost pressure sensor, vacuum leak or turbo vanes jammed.

Good power than loosing after extending driving (usually constant speeds) mostly jamming turbo vanes.

Cats usually give low power all the time, sometimes after changing the cats the air mass meter dies (it would already be failing, but the sudden increase in air flow takes it beyond it's useful range and trips a new code).


Cats on CDI2 engines (mostly ML270) regularly blocked up in Australia, CDI3 engines rarely block cats unless the driver is particularly gentle. This is due to fuel being more finely atomised/less soot on the CDI3 and later engines. "

How many Km has the car done ?

Be sure to let us know of the outcome. Thanks.

forfoxsake

Hi. Carsey, Thanks for your reply. the car has done 97K miles and is fine running then loses power for a couple of seconds then picks up again and is back to normal, it seems like an intermittant electrical problem as it loses power anytime during driving, accelerating and at all speeds. Some days it does it more than others..........very strange.

Carsy

As there is no spark ignition it can only be a fuel or air problem. To my mind more likely fuel starvation.

You will need to have a good experienced mechanic check it out & do some fuel pressure tests ect.

Good luck.

forfoxsake

Thanks Carsey, I'll let you know how i get on

john scott

Hi There

Did you get to the bottom of this?
I have a 2009 C220 CDI and It has suffered this in a minor way for about 4 years!

Initially the incidents happened perhaps once a month and doing a lot of miles it didnt cause me any stress.

I would be driving at pretty well any speed, and it would be quite abrupt like I had slipped my foot off the accelerator. Then perhap 5 seconds later it would pass and drive perfectly normally.

I dont do so much mileage now but it has increased from once a month to perhaps 6-7 times in a 100 mile journey. The length of the power loss has increasd to maybe 10 seconds and once last night I thought it wasnt coming back.

Perhaps related but if I have been driving quite cautiously for a while if I touch the throttle to overtake the car drops into limp mode with warning lights etc. Whilst still rolling along I turn off the ignition and on again and it resets without fail and we are back to normal. My local garage said I need to drive it a bit harder to clean up the deposits a bit.

Your cutting out sounds so like mine I am curious to see if it was the Mass Air Flow sensor or a pierced vaccum pipe. I had though my headlamp angle looked low recently so perhaps it is a vacuum loss problem