A207 engine 'hesitates' under cold acceleration

[Automac29]

I have a 2015 A207 E-Class E220 BlueTec AMG-line Cabriolet 2015 turbo-diesel auto. When the engine is cold I experience slight 'hesitations' as I accelerate for about the first half mile after which it clears as the engine warms up. I have put a pot of injector cleaner and another of turbo cleaner into the fuel without change. The MB dealer Star analyser shows no faults and has checked the engine / transmission for loose components. Any thoughts from you wise club members please?

 

[markjay]

Is this a new phenomenon? The 7g+ gearbox is notoriously harsh when cold.

BTW, normally I would suggest updating the firmware on the engine ECU and the transmission TCU, but in the case of BlueTEC cars you may end-up with the much-dreaded Dieselgate update... so I would look at updating the software only if the car is not included in the emissions update recall, or if the update has already been applied anyway.

 

[Automac29]

Is this a new phenomenon? The 7g+ gearbox is notoriously harsh when cold.

BTW, normally I would suggest updating the firmware on the engine ECU and the transmission TCU, but in the case of BlueTEC cars you may end-up with the much-dreaded Dieselgate update... so I would look at updating the software only if the car is not included in the emissions update recall, or if the update has already been applied anyway.

MarkJay - many thanks for your most useful reply. The car is 'new' to me so it is only me now finding it to be 'hesitating' and scratching my head - but i guess that it must have been this way for 'always'. I'm going to the MB dealer for a warranty issue on the 'Collision prevention Assist' being inoperative tomorrow and will print your helpful reply and see what they say. Again thanks!

 

[geoffus]

Let us know how you get on.

 

[Automac29]

'Collision prevention Assist' now sorted (one 'radar' replaced). Dealer tech says I have latest firmware for engine and transmission. In the few days since visiting the dealer I have not noticed the previous 'hesitation'. Could it be that either replacing the 'radar' stopped the car 'thinking' about going into some limp-home mode OR am I perhaps getting more used to it (and just driving better ) as the car is distinctly different to drive than my old 2006 CLK 350 petrol car owned for the past 9 years? Also, night time ambient temps are now higher than mid-Feb when I first noticed this...

Final thought is that I will see if my local MB Indie can do a gearbox oil change in due course. In the CLK there was a 'sump' below the box that had to be removed entirely and the auto-transmission specialist that I used to change the "sealed for life" CLK box oil said that was a significant source of his box-rebuild revenues because "sealed for life" meant a car-lifetime of circulating particles of swarf. It might just be a prudent good move!