Stutter when easing off gas at motorway speeds CLS 350d

[Richtjam]

Good day,
CLS 350d, year 2016, W218, 66k miles.

Strange issue of car stutter when easing off the gas pedal at motorway speeds, it for sure ruins the motorway cruise and just wondering if anybody out there has any experience.

Accelerate to overtake on motorway with no issues, but when I ease off the gas to reduce speed the car does a hiccup/stutter for about 2 seconds.
Very noticeable to driver and passengers.

No gear change takes place and no blip on rev counter is visible. Normally in D9 at about 1500 revs but also does it at lower speeds in the 50 to 70 range when easing off the gas.
Stutter not noticeable at speeds below 50mph but the faster I go the more of a stutter I receive.

If I lift all the way off the gas pedal then no stutter, only does it when easing off to reduce the speed.
Car has been doing it for well over a month , had B service end of November at my trusted independent garage with no fault codes evident and the auto transmission was reset to see if that cleared the issue.

Now it doesn't do it every time and I can try and make the stutter happen by accelerating and easing off the gas to demonstrate it.

I use the so called premium fuels and did put some injector cleaner through the fuel system but this has not helped the situation.

I will go back to my indy garage and see what they say.
Car is under 1 year MB warranty but the replacement of a Nox sensor in October at my local main dealer was a bit of a palaver and I dread dealing with them again.

I bought the current CLS 350d Premium Plus in July 2021 from a main dealer and this is my 2nd CLS as I had a 2010 CLS 350cdi Grand Edition for 8 years and actually shipped it to Australia with me when I moved there. I now live back in the UK so left the older CLS down under and got myself another one.

Thanks for your assistance and Merry Christmas.

 

[mioba]

Wecome to the forum,

If the car is under warranty, then that is the first port of call - to the dealer. Failing that, use a recognised mercedes independent.

Sounds like a vac leak, or could be the turbo actuator starting to fail (they can be purchased seperately). Make sure the actuator levers move freely and give it a shot of oil.

 

[mattkh]

Good day,

I had a 2010 CLS 350cdi Grand Edition and actually shipped it to Australia

At what cost..?

 

[dry run]

Welcome

 

[Richtjam]

At what cost..?

Hi, back in January 2013 to get the car onto a Hoegh Autoliner, Car Carrier ship from Southampton to Brisbane was 450 GBP + 200 GBP insurance so actually quite cheap to send a car all that way.
When the car gets there you have registration, GST, Import Duty, compliance checks costs etc and that came to 5500 GBP including the fee from Iron Lady imports who arrange the whole process.
Why go to the expense? - The CLS was 3 years old and it would have cost me considerably more to buy the same vehicle in Australia (actually couldn't as mine was first CLS 350cdi in Australia as the CLS's in Oz were petrol at that time). To sell car in UK and then buy something similar in Australia would be a big loss so better to keep and ship it. You can only do this if you are immigrating to Australia an you need to have owned the car for more than 1 year. This is so you don't buy a highly priced desirable car and ship to Oz to make a profit just before you leave the UK. Insuring the CLS in Australia was a pain as it couldn't be found on any database due to the diesel engine so I went with a specialist insurer (Shannons).
I returned to the UK in 2018 and sold the CLS for a lot more than I would have got selling it here in the UK so it worked out well in the end.

 

[Richtjam]

Wecome to the forum,

If the car is under warranty, then that is the first port of call - to the dealer. Failing that, use a recognised mercedes independent.

Sounds like a vac leak, or could be the turbo actuator starting to fail (they can be purchased seperately). Make sure the actuator levers move freely and give it a shot of oil.

Thanks for your input, much appreciated. Spoke with my local Independent MB specialist today and he agrees that best to go back to MB as car still has 7 months MB warranty left. No alarm codes present so not much he can do without stripping bits out and that costs money.
Looks like I will have to brave it out with the local main dealer. I bought the car from MB Colchester but live on the Wirral so will give MB Cheshire Oaks a go.
Thanks again.

 

[Manc Rick]

I understand your lack of faith with the Mb dealerships (my experience also) however I can say that I have been relatively impressed with Mb of Cheshire Oaks. I recently attended with a noise coming from the rear suspension (all components appeared to be fine so I was puzzled). They immediately sent a Master Tech to come out in the car with me and he diagnosed the noise immediately by ear only (it was the rear shock absorbers that had failed internally, which explains why all looked well on (my) visual inspection.

Both shocks changed under warranty without quibble.

It depends who you get working on the diagnosis, but I was impressed with the master technician and that the dealership didn’t waste my time. Previous (unrelated) experiences elsewhere have resulted in me leaving them with a car only to be called up at tea time to be told “we’ve road tested the vehicle sir and unfortunately we can’t hear any noise”.

If it requires specific actions to be able to recreate the problem, I would consider asking for a technician to come out with you so that you can demonstrate the problem.

Either that or leave them to scan it for codes and hope that it has logged a fault code. If not, then they will probably suggest that you demonstrate the problem.

I’d guess turbo related aswell or vac leak as suggested by previous posters.

 

[Richtjam]

I understand your lack of faith with the Mb dealerships (my experience also) however I can say that I have been relatively impressed with Mb of Cheshire Oaks. I recently attended with a noise coming from the rear suspension (all components appeared to be fine so I was puzzled). They immediately sent a Master Tech to come out in the car with me and he diagnosed the noise immediately by ear only (it was the rear shock absorbers that had failed internally, which explains why all looked well on (my) visual inspection.

Both shocks changed under warranty without quibble.

It depends who you get working on the diagnosis, but I was impressed with the master technician and that the dealership didn’t waste my time. Previous (unrelated) experiences elsewhere have resulted in me leaving them with a car only to be called up at tea time to be told “we’ve road tested the vehicle sir and unfortunately we can’t hear any noise”.

If it requires specific actions to be able to recreate the problem, I would consider asking for a technician to come out with you so that you can demonstrate the problem.

Either that or leave them to scan it for codes and hope that it has logged a fault code. If not, then they will probably suggest that you demonstrate the problem.

I’d guess turbo related aswell or vac leak as suggested by previous posters.

Thanks for the information.

I had a NOx sensor replaced at Cheshire Oaks in October so familiar with the routine there and managed to get booked in for 29th December check up.

No fault codes present when the local MB Indy checked so a drive with a technician is needed.

Thanks again for your information and festive greetings.

 

[Botus]

has the car has all engine emission and NOx sensor updates ?

this is a total fiasco and most appear to have been done to a part mix and match standard - to save a few pence many haven't been fitted with the last functioning NOx sensor type. If your indy can't guarantee he updated the part listing applying three software updates and using version 3 NOx sensor - highly likely faulty NOx sensor on the car

there's a post about the fun - https://forums.mercedesclub.org.uk/index.php?threads/nox-light.192180/ - until we know its on Mk3 NOx sensors and current software and you've ran a tank of decent tractor fuel is there much point if we don't have any fault codes

 

[Richtjam]

has the car has all engine emission and NOx sensor updates ?

this is a total fiasco and most appear to have been done to a part mix and match standard - to save a few pence many haven't been fitted with the last functioning NOx sensor type. If your indy can't guarantee he updated the part listing applying three software updates and using version 3 NOx sensor - highly likely faulty NOx sensor on the car

there's a post about the fun - https://forums.mercedesclub.org.uk/index.php?threads/nox-light.192180/ - until we know its on Mk3 NOx sensors and current software and you've ran a tank of decent tractor fuel is there much point if we don't have any fault codes

I bought the CLS 23rd July 2021 from MB Main Dealer about 300 miles away from home. Drive home was great but amber EML on the following day.
Went to local MB Main Dealer beginning August for diagnostics, fault identified as downstream Nox sensor.
Nox sensor ordered and then replaced 2 months later, all covered under MB used car warranty.
The wrong Nox sensor was ordered and that added to the delay in sorting the EML.

Nox sensor replacement carried out at MB Main Dealer so would like to think they performed all the required software updates. Car going back in for MB Main Dealer check on 29th so will see what they say.

 

[Richtjam]

Car went in to MB Dealer for diagnostics 29th December. With Covid restriction the technician is not allowed to come out in the car with me to identify the issue so I left a note in car highlighting the issue of car stuttering when easing off gas at speeds above 50mph and very noticeable on motorways.

MB called up later to say all checked, software updated and test drive was great.

Picked the car up and straight onto motorway and issue is still present.
Took car for good motorway drive and no difference after visit to the garage.

Checked the vehicle dash cam to see how the test drive went and the technician drive consisted of less than 2 minutes on motorway to 1st junction and then return of less than 2m where car was in traffic and not up to cruising speed.
Between the short motorway trips there was also a 6 minute period parked up where a phone call was taken.
Not good enough for test drive to check for the issue that car was submitted for in the first place.

Have messaged assistant service manager and will chase up when all the holiday stuff is over.

 

[Manc Rick]

To be honest I’m surprised they actually took it on the motorway at all, as usually their ‘road tests’ consist of a drive around the carpark and round the block if you’re lucky.

Seems all too common that dealers perform a quick software update and hope that the problem is fixed. They are under pressure to get cars in and out in a little time as possible.

Totally unacceptable and I hope you get this sorted without too much more fuss.

 

[mioba]

Its really a peev that they dont test things properly and think customers have all the time in the world to yoyo back and forwards to the dealers after an apparent fix.

 

[Richtjam]

To be honest I’m surprised they actually took it on the motorway at all, as usually their ‘road tests’ consist of a drive around the carpark and round the block if you’re lucky.

Seems all too common that dealers perform a quick software update and hope that the problem is fixed. They are under pressure to get cars in and out in a little time as possible.

Totally unacceptable and I hope you get this sorted without too much more fuss.

Went back to main dealer (avoiding the MB booking system) and was allowed to take the Master Tech out for a motorway test drive. Issue has been acknowledged and car booked in again for further investigation.

 

[Wrighty2312]

Hi
Can I ask what the outcome to this was ? I’ve got the exact same symptoms and struggling to get a diagnosis

 

[dcl]

Hi
same problem W222 265,000 miles main dealer serviced
only clue stored fault injector 1
main dealer not interested any advice please