Slow/jerky transmission

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MowerMan65

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Location
Wick, UK
Driving
MG HS PHEV
Hi everyone - I have had my HS PHEV for about a month now and and although I love it there are a couple of issues I've noticed that I would be interested if anyone else is experiencing.

1) Ridiculously slow gear changes. When in EV mode there is a gear shift that occurs at about 45 mph. It literally takes a full second to shift. There's no power to accelerate while this is happening. This also occurs in 'auto' mode - when accelerating there is a HUGE 'flat spot' at 45 to 50 mph when it appears that both transmissions (the 4 speed electric and the 6 speed auto) want to shift at the same time. This can definitely be a problem if you are overtaking at the time. All the IC engine shifts are VERY slow. If these shifts were speeded up it would substantially improve acceleration (which is already brutal as long as you avoid the 50 mph 'hole').

2) When accelerating normally in 'auto' mode, car seems to 'jerk'.....difficult to describe but it manifests itself in the same way an intermittent misfire in an old manual transmission car would. It's noticeable to passengers with no pre-warning - 'daddy why is the car shaking' type comments. It's obviously not actually a misfire but that's what it feels like. Is the transmission actually a CVT and do I have a slipping belt? I've no idea what type of transmission is actually fitted and my MG dealer can't or won't tell me.
 
ransmission6-speed manual
6-speed DCT
7-speed Sportronic DCT
10-speed EDU II automatic (6-speed engine and 4-speed electric motor; PHEV)

I think you find that a CVT is used on a small car.​

take it back or contact the Tec department at MG. And ask them about it.
 
It isn’t CVT but that has nothing to do with vehicle size. Lexus use CVT on their RX450hybrid. The gear change delay is well documented on this forum.
 
MowerMan65 said:
Hi everyone - I have had my HS PHEV for about a month now and and although I love it there are a couple of issues I've noticed that I would be interested if anyone else is experiencing.

1) Ridiculously slow gear changes. When in EV mode there is a gear shift that occurs at about 45 mph. It literally takes a full second to shift. There's no power to accelerate while this is happening. This also occurs in 'auto' mode - when accelerating there is a HUGE 'flat spot' at 45 to 50 mph when it appears that both transmissions (the 4 speed electric and the 6 speed auto) want to shift at the same time. This can definitely be a problem if you are overtaking at the time. All the IC engine shifts are VERY slow. If these shifts were speeded up it would substantially improve acceleration (which is already brutal as long as you avoid the 50 mph 'hole').

2) When accelerating normally in 'auto' mode, car seems to 'jerk'.....difficult to describe but it manifests itself in the same way an intermittent misfire in an old manual transmission car would. It's noticeable to passengers with no pre-warning - 'daddy why is the car shaking' type comments. It's obviously not actually a misfire but that's what it feels like. Is the transmission actually a CVT and do I have a slipping belt? I've no idea what type of transmission is actually fitted and my MG dealer can't or won't tell me.
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i'm having the exact same feeling, it's a little jerky in hybrid mode, like it cannot completely 'dose' the ICE/EV power when combined, seems a bit like the ICE switches between slight pulling & idling.
it's very pronounced from the point the ICE kicks in (40km/h) up to 80-90km/h , at highway speed it's more composed.
i was hoping it to be a software update sometime.
i dont get shift lag in hybrid mode, only in EV around 80km/h, the boxes never shifts at the same time, also i dont feel the 6 speed to be slow, it does have a somewhat 'funny' shifting pattern, but the shifts seems quick and comfortable. It might actually be a CVT as you say, it feels way different from my previous DCT, more like the Kuga PHEV with CVT (with artificial 'shifts') , that surely would explain why it revs so much when ICE kicks in, also it's probably a lot easier to incorporate with an E motor and planetary E-box.

is no one else feeling the jerkiness ?
 
I have just been to see my sales person and asked the question is the gearbox a CVT? He has not opened one up to look or seen the workshop manual but to his knowledge it’s a DCT and sure it has not belts to his knowledge. we also had a conversation about the change delay and agreed could be software but no knowledge of a upgrade at this time.
 
OK..... So if it's not belts, and by definition gear wheels can't slip - that leaves some sort of clutch fault? If others have noticed this then I have to assume it's not an actual mechanical fault with my car.....hopefully it's a software issue that gets patched sooner rather than later. It spoils an otherwise excellent driving experience.
 
If you read the brochure or search online it is well documented the gearbox is NOT CVT!!!! It is a 6speed DCT for the ICE with a 4speed DCT for the EV mode. This gear change delay is covered in threads elsewhere on here so am struggling to understand some of this discussion. Yes, there is clearly an issue in need of a software fix.
 
The slow gear changes are only half of the problem. It's the jerkiness when the ICE cuts in that I wanted clarification about - specifically is it just my car or did anyone else notice it. I haven't seen it mentioned elsewhere.
Yes I saw the claim that it's a DCT. So why does it do a damn good impression of an old 3-speed slushbox with a slipping stator? Or a cvt with a worn belt? Without prior knowledge I would NEVER guess it's a DCT from the way it drives. DCT boxes usually have very positive virtually instant shifts.
So I was looking for confirmation that the specs haven't changed. The Chinese have been known to do that.
 
I would say its not a jerkiness when the ICE comes in but a increase in power, the car seem to pick up and when it cuts out a decrease in power. My car is smooth to me,
take it back to your garage if not happy and get them to check it out.
 
I read an australian review stating that it actually is an old style box with converter in oil, that makes sense as it sure don't feel like dct. For sure the 4 speed is not dct either, as it's a planetary box for the E motor. I don't think any dct would withstand the momentum from the e motor very long.
 
Jto said:
I would say its not a jerkiness when the ICE comes in but a increase in power, the car seem to pick up and when it cuts out a decrease in power. My car is smooth to me,
take it back to your garage if not happy and get them to check it out.
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I've been out this morning....the jerking is there all the way from a standing start if the ICE is running. It's definitely a problem with the ICE transmission - if you're not seeing it then my car needs looking at........
 
Am going out soon and will be using the ICE when it starts i do feel a small vibration under my foot so you know it’s working and feel more power to the drive. There no jerking but will let know when I get back.
 
Just been out up the hill start in ev then ICE cut in feel upgrade in power smooth as went up the gears to me no jerking at all .
When do you get a jerk, is very physical jerk?
 
Mine feels like its a little indecisive of the amount of power it needs to mix, its not so bad but it's there. At highway speeds it's almost gone
 
JABO said:
i'm having the exact same feeling, it's a little jerky in hybrid mode, like it cannot completely 'dose' the ICE/EV power when combined, seems a bit like the ICE switches between slight pulling & idling.
it's very pronounced from the point the ICE kicks in (40km/h) up to 80-90km/h , at highway speed it's more composed.
i was hoping it to be a software update sometime.
i dont get shift lag in hybrid mode, only in EV around 80km/h, the boxes never shifts at the same time, also i dont feel the 6 speed to be slow, it does have a somewhat 'funny' shifting pattern, but the shifts seems quick and comfortable. It might actually be a CVT as you say, it feels way different from my previous DCT, more like the Kuga PHEV with CVT (with artificial 'shifts') , that surely would explain why it revs so much when ICE kicks in, also it's probably a lot easier to incorporate with an E motor and planetary E-box.

is no one else feeling the jerkiness ?
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As I mentioned there is a Hybrid gear box update, for me ICE is always jerky compared to EV. MG HS Phev's auto gear box can't be compared with high end auto gear boxes like those in Merc but compared to budget crap I have driven, its not too bad :). My previous car Oultander 2.0 was way worse with ICE.
 
hermitdave said:
As I mentioned there is a Hybrid gear box update, for me ICE is always jerky compared to EV. MG HS Phev's auto gear box can't be compared with high end auto gear boxes like those in Merc but compared to budget crap I have driven, its not too bad :). My previous car Oultander 2.0 was way worse with ICE.
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Hybrid gearbox update is news to me. My dealer told me there's an update available that has something to do with the HV battery, but it's not a mandatory update. Didn't mention anything about a gearbox update. I'll ask again.
 
MowerMan65 said:
Hybrid gearbox update is news to me. My dealer told me there's an update available that has something to do with the HV battery, but it's not a mandatory update. Didn't mention anything about a gearbox update. I'll ask again.
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@MilesperkWh posted about Infotainment and BMS update a while ago and I rang up and booked for those. When the car came out I was told they applied BMS and Hybrid gear box update. Let me find if they gave me any paperwork
 
hermitdave said:
@MilesperkWh posted about Infotainment and BMS update a while ago and I rang up and booked for those. When the car came out I was told they applied BMS and Hybrid gear box update. Let me find if they gave me any paperwork
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OK.....did it change the jerky acceleration or solve the massive pause at about 50 mph when accelerating hard?
 
Obliviously same problem here. The only workaround I found is to raise the foot when hitting 80km/h (how you would do if you had a manual gearbox) and then floor it again. Gear shift is then faster than if you kept foot down
 
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