slight hesitation when accelerating from slow speed

[barnaclebill15]

Have noticed a problem that only happens sometimes, slow down for a junction or roundabout see a gap try to speed up but nothing happens, car just keeps going slow then after a couple of seconds speeds up. Does not happen every time and you can not reproduce it when in park and reving the engine. It has not happened at say 30, 40 50 just when your rolling up to the roundabout then the next few times all is ok then it does it again, just tried looking at the codes on my MB code scanner but just nothing.

 

[Snake Charmer]

My E320 CDI has what I though was a Comfort and Sport button, the book says different it is Comfort and Standard. The car is very lethargic in Comfort mode and most noticeably pulling onto roundabouts when moving as very unresponsive.

 

[barnaclebill15]

I am in S mode and it was not like this before, I have modified my driving as I cant risk pulling out unless the road is clear

 

[Snake Charmer]

Have you checked the gearbox oil level and colour?

 

[barnaclebill15]

checked transmission level on the flat with engine running up to temperature, all normal.
tried reving in neutral but cannot replicate what happens only when at low speed and less than 800 rpm and I try to accelerate nothing happens sometimes for 2 or 3 seconds, I flutter the accelerator and it suddenly picks up.

 

[alexanderfoti]

Could be the start of failing throttle pedal (sensor). They eventually log a fault but sometimes do this first.

 

[Chrishazle]

I have a similar problem on my S204, pulling say onto a roundabout from stationary it takes 1/2 second for the GB to respond and move. makes no difference if I'm in C or S mode, just something I've learnt to live with!

 

[mattkh]

I flutter the accelerator and it suddenly picks up.

There is your answer.
Check for any play in the pedal mechanism.

 

[barnaclebill15]

Thanks but Why does it not happen when I test it in neutral or park, it never hesitates that is the puzzle

 

[mattkh]

does it not happen when I test it in neutral or park, it never hesitates that is the puzzle

In that case, it points to the transfer of power to the wheels.

 

[mattkh]

What is the mileage..?
Any EGR news.

 

[barnaclebill15]

196k had a new egr unit fitted three months ago, today it only happened a few times but one time the engine sounded rough for a couple of seconds then t behaved. On the way home tonight in traffic stop start never flickered and on the motorway flew along as smooth as you like.

 

[Headhurts]

My previous car with the 7g box in Eco mode used to do this and it did use to catch me out sometimes the car being very lethargic.

My current car with the 9G box is much better but I mostly use sport mode.

I know you said you have not noticed this before but it seems a reset of the gearbox may be worth a try.

I have no technical knowledge this info is just from a user who has experienced exactly those symptoms on previous car.

Robin

 

[mattkh]

..... but one time the engine sounded rough for a couple of seconds

Was the car moving when this happened..?

 

[barnaclebill15]

moving slowly

 

[barnaclebill15]

Update, tried it in C comfort mode, it was ok for about 10 minutes but then same problem so at the next lights put it in park and changed back to S sport, since then it has behaved normally. I had not changed C and S postions for a long time so wonder if it was a poor contact

 

[barnaclebill15]

It has been normal for a couple of weeks now, had it booked in with my indie for this Friday but think I will cancel, no codes showing on my MB reader and car is behaving itself. Starting to wonder if it was a bad tank of supermarket diesel.