[kangarooingmgzs]

Hi All,

I am so happy to have found this thread. We picked up a brand new MG ZS Exclusive 1.0T in June 2020. The Wife and I have taken the car back twice to the dealership because of this mis-firing/hesitation issue that everyone on this forum is talking about.
I agree with the not-revving beyond 3-4000rpm. I put my foot all the way down on the accelerator and the car just wouldn't rev past the limit as above.
Letting the car idle - it jumps at times suggesting a mis-fire.
The car feels underpowered when driving or 'holding back', suggesting a fuel/air ratio mixture is running lean.
Not changing down gears when you put your foot down
Smell of burning/friction after short drives

All of the replies I have read on this thread, i'm like, yeah, that's happened to me. I am just happy its not just me and seems to be a major issuing affecting a lot owners.

When we took it in, the first excuse the technician came up with was we may have put dodgy petrol in and that is what is causing the problem. They changed the particle sensor as a precaution and handed the car back to us. It was better at first, but now all the problems have come back again two months down the line.

I do not agree with the fact that we have to drive the car for a long run every weekend to ensure no build up of soot which requires the 'regeneration' process. I am now also worried about this stalling environment with the stop/start.

We purchased a new car to avoid all the issues that you sometimes encounter with used cars.
We also purchased the car in cash, so I am not sure what rights we have under the consumer act to either return the car or request a replacement.
I work overseas, so my wife is stuck with dealing with the problems along with school runs, etc. She needs a reliable car!
I feel slightly happier that we are not alone, but we need to figure out what our rights are.
Can we go for a recall? or can we just return the car requesting a full refund? I need to read the Consumer Act carefully.

Send me a private message - I have all the answers you need on this issue and what your rights are and what you need to do without delay,.

 

[JonM]

PPF only on Direct injection engine cars

It is a shame to hear that you are having issues with the car at such an early age, I had a similar issue with the 1.5 litre engine in my brand new 2018 model ZS where it would constantly stall when trying to move off from a standstill. The problem eventually got looked at by the dealer and the issue has almost gone away so there is hope that SAIC/MG can find a solution for your issue.

The engine is designed by Opel and is based on their Small Gasoline engine:

GM small gasoline engine - Wikipedia

The engine is a direct injection model which is supposed to reduce CO2 but has been found that it isn't as clean as it was thought to be which is why they have had to install the Petrol Particulate Filter (PPF) which is also known as Gasoline Particulate Filter. My own ZS SUV has an indirect injection based engine which is why it does not need to have one fitted.

The filter if it is like the diesel version should regenerate when it gets hot enough, this is done passively however the following should be noted:

Gasoline particulate filters (GPF) have been introduced to reduce particle number emissions from GDI vehicles. The filters utilize wall-flow substrates first developed for diesel particulate filters. The GPF regenerates passively, but an active regeneration assist is needed to prevent filter plugging during low temperature duty cycles. Ash has an impact on GPF performance and—if the GPF is coated with a three-way catalyst—can be a source of catalyst poisoning.

In your case it could be that there is a blockage or if there is a sensor it could be misreading something during the active regeneration.

The above information about active regeneration on PPF's can be found here:

Gasoline Particulate Filters

Cheers..

Hi,

You state "The problem eventually got looked at by the dealer and the issue has almost gone away..." Do you know what the dealer did ? My car has a similar problem and while I do not want to, I am thinking of getting rid of the car because of the rough running issue.

 

[mattykan]

Hi,

You state "The problem eventually got looked at by the dealer and the issue has almost gone away..." Do you know what the dealer did ? My car has a similar problem and while I do not want to, I am thinking of getting rid of the car because of the rough running issue.

The MG dealer Apple MG performed 2 different ECU updates on the car, with the second one finally fixing the issue once and for all as I have not had the stalling issues or the lumpy running when cold since this was done.

Each time the car's ECU was updated, the adaptions were reset so the car had to learn my driving style again.

I found out that because of the tough EU emissions laws, the engines have been tuned to have very lean running which unfortunate as the engine are not very "clean" in the first instance.

In China where the car is made, the petrol that they use has a lower octane rating and is quite rubbish compared to the stuff that we have so the engines are designed to be quite rough and ready and almost to the point of agricultural since they don't have to worry as much about emissions over there.

When in the UK, it looks like the engine has to be "re-turned" using the ECU updates in order to make it behave better with our petrol.

I am surprised that your MG dealer hasn't offered this to you.

MG Motor UK paid for these under warranty so I didn't get to see the paperwork but I was told enough by the master technician Malcolm.

Cheers..

 

[JonM]

The MG dealer Apple MG performed 2 different ECU updates on the car, with the second one finally fixing the issue once and for all as I have not had the stalling issues or the lumpy running when cold since this was done.

Each time the car's ECU was updated, the adaptions were reset so the car had to learn my driving style again.

I found out that because of the tough EU emissions laws, the engines have been tuned to have very lean running which unfortunate as the engine are not very "clean" in the first instance.

In China where the car is made, the petrol that they use has a lower octane rating and is quite rubbish compared to the stuff that we have so the engines are designed to be quite rough and ready and almost to the point of agricultural since they don't have to worry as much about emissions over there.

When in the UK, it looks like the engine has to be "re-turned" using the ECU updates in order to make it behave better with our petrol.

I am surprised that your MG dealer hasn't offered this to you.

MG Motor UK paid for these under warranty so I didn't get to see the paperwork but I was told enough by the master technician Malcolm.

Cheers..

Thanks for the information. The Dealer has carried out at least one update and changed the water temperature sensor (about a year ago, haven’t had the chance to get it back to the Dealer due to coronavirus issues). When I got the car back, the engine was still warm so it performed well on the way home. On really cold days the engine is not happy at all and on occasion, the engine “kicks “ as if the ignition is turned off then on again very quickly. A shame as I’ve had nothing like the issues with my ZS that other folks have had with theirs. Regards.

 

[mattykan]

Thanks for the information. The Dealer has carried out at least one update and changed the water temperature sensor (about a year ago, haven’t had the chance to get it back to the Dealer due to coronavirus issues). When I got the car back, the engine was still warm so it performed well on the way home. On really cold days the engine is not happy at all and on occasion, the engine “kicks “ as if the ignition is turned off then on again very quickly. A shame as I’ve had nothing like the issues with my ZS that other folks have had with theirs. Regards.

The car has an anti-stall function which is meant to automatically restart the engine if it detects that it's stalled.

It's not meant to do that unless there is something not quite right somewhere, especially if it does it when idling.

Do you know if you've had the crank position sensor replaced as several owners have had this changed as it could be a dodgy batch?

Read more here:

https://www.honestjohn.co.uk/forum/post/127881/mg-zs-2017-1-5

Cheers..

 

[JonM]

The car has an anti-stall function which is meant to automatically restart the engine if it detects that it's stalled.

It's not meant to do that unless there is something not quite right somewhere, especially if it does it when idling.

Do you know if you've had the crank position sensor replaced as several owners have had this changed as it could be a dodgy batch?

Read more here:

https://www.honestjohn.co.uk/forum/post/127881/mg-zs-2017-1-5

Cheers..

Hi, the engine has stalled a couple of times but not during the last year. On a really cold start, the engine rpm “hunts” on idle and I find it best to let it warm up a little before driving. If the Dealership has changed the crankshaft sensor, I was not informed. All I know of is an “update” and the water temp sensor change. There is a different MG Dealership a few miles from my current location. I’ll try and get the car booked in for a diagnostic there. Regards.

 

[mattykan]

Hi, the engine has stalled a couple of times but not during the last year. On a really cold start, the engine rpm “hunts” on idle and I find it best to let it warm up a little before driving. If the Dealership has changed the crankshaft sensor, I was not informed. All I know of is an “update” and the water temp sensor change. There is a different MG Dealership a few miles from my current location. I’ll try and get the car booked in for a diagnostic there. Regards.

A second opinion is recommended as it sounds like the first dealership is having problems with fixing a known issue.

The engine in my own car when cold, idles at around 1100 RPM then after a couple of minutes this drops to about 800 RPM.

Good luck!

Cheers..