MG4 Reduction Gearbox Oil Leak

German MG4 Facebook group yesterday. Newly delivered car, gearbox error after 300 km. I wonder when that specific car was built and what breather is fitted.

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Well, the metre long tube high up behind rear bumper with the original ball valve breather removed (and a plug with a 1mm hole in it's place) idea hasn't cured the leak either.
The shiny stains creeping all along the outside of the bumper are getting embarrassing, looks like the local tom cats have been busy on it.
Really amazed by how much oil this thing can push out, and how far.

Have ordered an alloy fuel filter housing to try in- line on the pipe, maybe the wide spot will drop the speed and pressure enough to allow the oil to collect there .
Beyond that, I'm planning trying to use the side mounted oil filler as the breather to see if a different location can cure it.
It's a big bugger though, M16. Available, bolts seem to be 8.8 tensile or above and tricky to drill a clean hole through, nylon ones are available but usually the wrong threat pitch.

Oh well fingers crossed that the physics are in my favour and the bottle works, must go and wash my bumper :sick:
 
Well, the metre long tube high up behind rear bumper with the original ball valve breather removed (and a plug with a 1mm hole in it's place) idea hasn't cured the leak either.
The shiny stains creeping all along the outside of the bumper are getting embarrassing, looks like the local tom cats have been busy on it.
Really amazed by how much oil this thing can push out, and how far.

Have ordered an alloy fuel filter housing to try in- line on the pipe, maybe the wide spot will drop the speed and pressure enough to allow the oil to collect there .
Beyond that, I'm planning trying to use the side mounted oil filler as the breather to see if a different location can cure it.
It's a big bugger though, M16. Available, bolts seem to be 8.8 tensile or above and tricky to drill a clean hole through, nylon ones are available but usually the wrong threat pitch.

Oh well fingers crossed that the physics are in my favour and the bottle works, must go and wash my bumper :sick:
Disappointing Macadoodle ...
1mm for the air to escape, not too little?
 
I had my MG4 in at the start of Feb for the oil leak, picked it back up on Tuesday (28th!). They dealerships invoice states replaced the breather hose. Took it back to them today as it is still leaking. Lets see what they say/do for it this time.

As an edit for knowledge, I do 60 mile motorway round trip daily as a commute.
 
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Hi Les, did you get back in touch with the Ombudsman? Even the MG website says they are a member:
View attachment 15568
Hi Ayoll and leeP, you where both correct in pointing out about MGs accreditation To the ombudsman’s service, I have manage to get in touch with them again this morning and they have confirmed that MG motors UK are, now on their services accreditation listing but only very recently and confirmed I had been wrongly informed.
But they also confirmed some of there dealers might not be, I Check mine again this morning and they or not on the MG side but are as Nissan dealers so I think that would mean if I had an issue with the dealer about something with the MG the ombudsman would be unable to help me and I would need to contact MG direct.

So I explained again about the on going oil leak issue with the 4 and that MG are still trying to resolve it be fitting new breathers lowering oil levels etc and they said that until have had chance to resolved the problem there is nothing further they can do and they also said they would only take any action on a case by case basis when I explained about us the forum members so it does not appear they can be of much help until MG have finished their efforts to cure it.
So I apologise if I miss lead the forum that was not my intention in anyway.
Les

Here is what the ombudsman told me I would need to do if I wanted them to consider any assistance with a claim. For my wife’s car.
This is an explanation and there are forms to fill out also.
Got the car back this afternoon dealers had it for more than 48 hrs fitted the new breather done a couple of software updates one of which was for the recall for the door locking issue which the assure me is now OK
Les.

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Disappointing Macadoodle ...
1mm for the air to escape, not too little?
It's possible I guess. When you consider the total volume of this box and the fact it only seems to get to 30 degrees above ambient temp, the pressure from expansion must be very low, hence I thought 1mm might be ok.
Will try a bigger hole while I wait for the bottle.
 
A vid would be the way to go, just really difficult to find a good location and secure fixing .

Short vertical tube didn't retain visible oil but the metre long one does. It has an unavoidable low spot where it dips down under a structural member before going up high behind the back bumper.
This low spot is solid with oil over several cm, like a sink or basin trap really, but a subtle curve rather than a 'u'.
The behind bumper idea might never work because of this trap effect :confused:
Ooh, that's interesting. When you say "solid with oil" do you mean its a clearly visible oil film or that the tube is full at the low point, like a sink trap? If it is indeed full then there's no way that is mist or foam but is definitely fling from the gears...breather is in The Wrong Place (tm).
 
Ooh, that's interesting. When you say "solid with oil" do you mean its a clearly visible oil film or that the tube is full at the low point, like a sink trap?
Yes, full like a sink trap over a few cm. So it will be holding a vacuum on the gearbox side of this 'blockage' which is probably counterproductive.
The only way I can see to get a vertical run with no low spots is through the boot floor !
There's actually a hole into the boot blanked with a grommet almost directly above the breather, maybe this is SAIC's 'breather version 3' route ?
 
Yes, full like a sink trap over a few cm. So it will be holding a vacuum on the gearbox side of this 'blockage' which is probably counterproductive.
The only way I can see to get a vertical run with no low spots is through the boot floor !
There's actually a hole into the boot blanked with a grommet almost directly above the breather, maybe this is SAIC's 'breather version 3' route ?
Can't wait for an internal oil fountain in my boot 🤩😂
 
Yes, full like a sink trap over a few cm. So it will be holding a vacuum on the gearbox side of this 'blockage' which is probably counterproductive.
The only way I can see to get a vertical run with no low spots is through the boot floor !
There's actually a hole into the boot blanked with a grommet almost directly above the breather, maybe this is SAIC's 'breather version 3' route ?
Well, that is indeed interesting. That's far too much to be a bit of foam and/or mist collecting but definitely looks like the unit is expelling liquid. It's weird because the unit I tested didn't do that.
 
Have not visited this post for a while as mine (after the new breather (Mark One I presume)) has not leaked. I also assume that the majority of the few thousand cars in the UK now are also not leaking, then has anyone a reason for those that dont leak? Identical boxes?
 
Have not visited this post for a while as mine (after the new breather (Mark One I presume)) has not leaked. I also assume that the majority of the few thousand cars in the UK now are also not leaking, then has anyone a reason for those that dont leak? Identical boxes?
This over 2500 post thread, has covered your points at some stage but it’s now that long it enviably starts to repeat itself.
It’s impossible to know at the moment how many are leaking. Not all owners are on here or report leaks, some won’t notice but will have a leak, some will notice and not report, some will not care, some will not have a leak yet but might get one later. Some have had a modified breather and still leak.
We are still not really any the wiser about versions of gearboxes and if for example newer cars have a different gearbox. Various variations of breather seem to be around. Some cars that don’t leak now might leak later under different driving conditions. Some might be fixed. Who knows? It‘a a mess really.
 
This over 2500 post thread, has covered your points at some stage but it’s now that long it enviably starts to repeat itself.
It’s impossible to know at the moment how many are leaking. Not all owners are on here or report leaks, some won’t notice but will have a leak, some will notice and not report, some will not care, some will not have a leak yet but might get one later. Some have had a modified breather and still leak.
We are still not really any the wiser about versions of gearboxes and if for example newer cars have a different gearbox. Various variations of breather seem to be around. Some cars that don’t leak now might leak later under different driving conditions. Some might be fixed. Who knows? It‘a a mess really.
Yes. It is a mess. It would REALLY help if MG got their act together, recalled all the cars that could be affected, produced a definitive fix and told us why some leak and some don't.
 
This over 2500 post thread, has covered your points at some stage but it’s now that long it enviably starts to repeat itself.
It’s impossible to know at the moment how many are leaking. Not all owners are on here or report leaks, some won’t notice but will have a leak, some will notice and not report, some will not care, some will not have a leak yet but might get one later. Some have had a modified breather and still leak.
We are still not really any the wiser about versions of gearboxes and if for example newer cars have a different gearbox. Various variations of breather seem to be around. Some cars that don’t leak now might leak later under different driving conditions. Some might be fixed. Who knows? It‘a a mess really.
I agree but looking back on these 2500+ Posts a lot are done by the same posters either repeating themselves are adding comment to emphasise their kicking of the MG brand or support.
In fact a few don't actually own the car!
I understand that forums are designed to encourage debate, but sometimes the repeated digs get a bit boring.
 

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