MG4 Restricted speed - weird

[Ayoull]

A frisky hill climb at 30% SOC is was the first time in 3 months that my SE throttled the power.
It came in quickly and disappeared quickly.
The motor will have an NTC sensor or whatever buried in the windings I would presume, something's reacting very quickly to thermal load for sure.
The fact that the dealer replaced bowfer's motor and he saw no difference would suggest it's the system's reading of the temp that's going wonky on some cars.

Most likely, another possibility is other manufacturers are restricting their motors to a lower rating from the get go, a common thing in my industry is to work to 90% of a piece of equipments rating to improve longevity and reliability.

MG could have chosen a motor and chose to run it at it's maximum rating, where as others may throttle from the get go, meaning unless thrashed continuously they wouldn't have to throttle back.

So a fix could be limiting say the 125kW motor to 112.5kW and the 150kW motor to 135kW this would solve alot of the power limiting issues if it is a thermal problem but would reduce over all power.

 

[bowfer]

Yes, I am not saying it doesn't overheat, just that this doesn't seem to be bowfer's issue: limiting power is different from a hard stop on top speed.

Yup, mine is a speed issue.
The car is deciding what top speed I’m getting on that day, then the power meter tumbles to whatever power percentage is required to hold that speed and no more.
Below this restricted speed I will still get 100% power on the gauge, although the car does feel more lethargic and ‘lumpy’ in its power delivery (so I can tell the speed restriction is imminent)

ANYWAY that’s me about set off to return the car to the dealer.
Neither they nor the finance company have said to do so, I’m just doing it to hopefully push things along.
Last drive in a 4….!

 

[Macadoodle]

MG could have chosen a motor and chose to run it at it's maximum rating, where as others may throttle from the get go, meaning unless thrashed continuously they wouldn't have to throttle back.

Are you seriously suggesting MG would have chosen to go down the cheapest route with their motor specs and then cover it up with cack handed software ?

Bloody ridiculous accusation

Yup, mine is a speed issue.
The car is deciding what top speed I’m getting on that day, then the power meter tumbles to whatever power percentage is required to hold that speed and no more.
Below this restricted speed I will still get 100% power on the gauge, although the car does feel more lethargic and ‘lumpy’ in its power delivery (so I can tell the speed restriction is imminent)

ANYWAY that’s me about set off to return the car to the dealer.
Neither they nor the finance company have said to do so, I’m just doing it to hopefully push things along.
Last drive in a 4….!

Hopefully the ' dump it and leggit' tactic will bring an end to your suffering bowfer. GOOD LUCK

 

[FiferMG4]

Yup, mine is a speed issue.
The car is deciding what top speed I’m getting on that day, then the power meter tumbles to whatever power percentage is required to hold that speed and no more.
Below this restricted speed I will still get 100% power on the gauge, although the car does feel more lethargic and ‘lumpy’ in its power delivery (so I can tell the speed restriction is imminent)

ANYWAY that’s me about set off to return the car to the dealer.
Neither they nor the finance company have said to do so, I’m just doing it to hopefully push things along.
Last drive in a 4….!

Too bad it didn’t work out for you as it should have done, Bowfer. Let us know how you get on with your next car.

 

[stevegus]

As something else to throw into the mix as possible root cause of motor overheating scenarios -

If the auto shutters dont open at the front to get heat out of the coolant (not on SE SR)

And if the circulation pump isnt running…

 

[Macadoodle]

I've a vision of bowfer opening his bedroom curtains tomorrow morning enjoying a satisfied stretch and yawn, only to find an upside down MG 4 dumped on his lawn.

 

[maverickz]

The battery and motors are different between SR and LR but may have the same overall design and manufacturer I suppose.

SR and LR got the same motor

 

[bowfer]

I've a vision of bowfer opening his bedroom curtains tomorrow morning enjoying a satisfied stretch and yawn, only to find an upside down MG 4 dumped on his lawn.

Parking the car upside down will be MG’s latest recommendation to stop the oil leak.

 

[tsedge]

SR and LR got the same motor

No, they are different - different peak and average power ratings and the LR drivetrain has different gearing.

 

[maverickz]

No, they are different - different peak and average power ratings and the LR drivetrain has different gearing.

I mean the motor itself is the same.
Not sure the drivetrain.

 

[tsedge]

I mean the motor itself is the same.
Not sure the drivetrain.

I don't think it is, according to the manual, unless you mean it is the same type of motor? But it is rated differently so a different version of the same family perhaps is what you meant?

 

[Ayoull]

I don't think it is, according to the manual, unless you mean it is the same type of motor? But it is rated differently so a different version of the same family perhaps is what you meant?

A quick Google does appear to confirm that both LR and SR models use the exact same motor namely:

United Automotive Electronics Co TZ180XS0951 which has a peak output of 150kW

 

[Deleted member 10041]

A quick Google does appear to confirm that both LR and SR models use the exact same motor namely:

United Automotive Electronics Co TZ180XS0951 which has a peak output of 150kW

That probably explains reports of SR and LR cars with the throttling back, thermal warnings scenario, the different battery chemistries, SOC etc could also contribute to what extent.

Still believe Bowfer's is a different problem again

 

[bowfer]

That probably explains reports of SR and LR cars with the throttling back, thermal warnings scenario, the different battery chemistries, SOC etc could also contribute to what extent.

Still believe Bowfer's is a different problem again

I think mine is related to asking for high speed when cold, to be honest.
( high speed…70mph….ha! )
But seeing as I’ve only had the car for less than 50% of the time since November, difficult for me to judge properly.

 

[maverickz]

A quick Google does appear to confirm that both LR and SR models use the exact same motor namely:

United Automotive Electronics Co TZ180XS0951 which has a peak output of 150kW

The same motor has 3 confirmed different outputs:
125kw MG4 SR
150kw MG4 Trophy
175kw (SAIC immotors L7 and LS7, motor fitted at the front axle, not like MG4)

Interesting motor spec between SR, Trophy and same motor on other car

Just reading some posts on chinese forums, someone noticed the rear drive motor actually are the same one cross 3 models: 125kw, 150KW and 175KW in the Immotors L7 (another SAIC brand) Below are photos from 3 different models. It seems like our SE SR motor has software lock to lock to 125KW.

www.mgevs.com

 

[Macadoodle]

175 kW ( about 240 hp) with an 80 kWh useable battery would the sweet spot for me

 

[Eber]

But seeing as I’ve only had the car for less than 50% of the time since November, difficult for me to judge properly.

Did your rejection work well?

 

[richlove]

Hi all, I excitedly collected my new MG4 SR SE from Perry's Preston on Saturday and I am sad and frustrated to report I'm experiencing the exact same symptoms as Bowfer.

It's a speed limit restriction that's being hit and the power delivery is adjusting against that limit. I've only driven the car a few times and had it several times and the speed limit hasn't been consistent had it around 70mph, 80mph, and way under 70mph. Think the SOC was less than 50% when it's been happening, today was <30%. What a disappointing start to ownership

Not really sure what to do, seems like there's no solution coming from MG so far.

Also, when i switch it to 'Sport' it shows 'Sport' on the screen behind the wheel, yet 'Snow' on the main central screen!? Anybody else seen this? I don't know which it's actually in.

 

[richlove]

Does anybody know if the 100% health charge for LFPs can be performed on any speed charger or does it need to be a slow (e.g. 7kW charger) ?

 

[siteguru]

It's expected to do balance charges on a wall box - or even on a domestic socket.