MG4 Reduction Gearbox Oil Leak

[Hagen]

Mine was built in N0, no leak yet.

Great! Is the 10th digit N or P?

 

[tsedge]

Great! Is the 10th digit N or P?

Mine is: LSJWH4091PN0xxxxx

 

[Hagen]

Thx!

 

[tsedge]

Thx!
View attachment 16141

Mine was built late November 22

 

[Hagen]

 

[Davemac278]

Mine is Trophy
Built 20th September 2022
10th digit on vin is N
11th N1
Picked up December England
After 40 miles oil leak
After 2 weeks modified breather fitted in January

No leak since

 

[Ayoull]

View attachment 16144

Leak yes and plant 2

 

[JuziWomble]

View attachment 16144

LSJWH4097NN1xxxxx - So a 22

 

[AndyL61]

It would need a couple of new owners, who after a fair bit of spirited driving, still have no oil leaks to be brave enough to drain the boxes and see how much comes out.
Big ask to be fair if you currently have no issues, would be very interesting results though.

On a separate note has anyone with the newest build dates been able to get under and have a look at the gearbox and see what, if any, type of modification they have on the breather.

Mine definitely has the modified breather, it hasn't leaked yet and has PN0 vin. We are in Cornwall on holiday at the moment so when I get back I will be checking again as it will then be after extended motorway driving .

 

[Rob66]

mone is trophy
built 23th November 22
LSJWH4096PNOXXX
no leak

 

[MG4London]

It’s been so long now have they fixed the leaking oil on all new mg4s?

 

[AndyL61]

It’s been so long now have they fixed the leaking oil on all new mg4s?

That's what we're trying to establish by owners sharing their information.

 

[MG4London]

I have my new SE model coming very soon, I will check very carefully underneath to look for any leaking oil

May even put something under the car that will show leaking oil even more obviously

 

[siteguru]

Like a litter tray?

 

[Hagen]

 

[AndyL61]

Nice pattern forming there !

 

[Veryfatbloke]

Location - England
Built - September 2022
Leak - No
VIN - LSJWH4093NN1*****

 

[wiz043]

There appears to be a pattern with the 2023 models not leaking according to the research here but I wonder if these cars have a modified breather or just have less oil put in them at birth or both as indicated by @Hagen. Dealers would not know and the Chinese manufacturer is certainly not going to tell anyone...they are renown for keeping secrets.
What we need is for someone who knows the 'old' breather design to check the latest model breather type and the amount of oil in the reduction gear box but I don't know how that can be achieved as I doubt dealers would be any help.
I applaud @Hagen for taking the time to do this research and it would be great if it is proven that those vehicles built after a certain date do not have this issue but my main concern is whether MG 'solved' the problem by a bandaid fix of just sharply reducing the amount of oil put in the 'box.

 

[Macadoodle]

There appears to be a pattern with the 2023 models not leaking according to the research here but I wonder if these cars have a modified breather or just have less oil put in them at birth or both as indicated by @Hagen. Dealers would not know and the Chinese manufacturer is certainly not going to tell anyone...they are renown for keeping secrets.
What we need is for someone who knows the 'old' breather design to check the latest model breather type and the amount of oil in the reduction gear box but I don't know how that can be achieved as I doubt dealers would be any help.
I applaud @Hagen for taking the time to do this research and it would be great if it is proven that those vehicles built after a certain date do not have this issue but my main concern is whether MG 'solved' the problem by a bandaid fix of just sharply reducing the amount of oil put in the 'box.

Unless there's a fundamental change to the design inside the box I would be very surprised if there's any way to stop the leaking with the current breather position and a decent oil volume inside.

I tried and tried. Now I know I don't have a team of clever engineers at my disposal but I saw first hand the eruption of oil every time you have 700ml or more in there.
Regardless of how long a pipe you use or how much you restrict it, or enlarge it, or coil it, you name it, it didn't work.
It's been over a week and I've covered more than 300 miles with the side mounted breather with a short pipe installed in the box's fill hole.
Pleased to say that the leak is no more, and I'm running with 900ml (refilled with 850ml allowing for some residual oil )
Unless MG has a recall to strip the gearbox and properly retrofit an oil deflector or whatever it actually needs I'm just going to stick with my own setup for as long as I own the car, at least I know it's getting lubricated which is the main thing.

 

[Ian Key]

Is it possible that the leak-proof modified breather has an extension inside the box that takes the entrance to the breather away from the oil being thrown up by the gears?