MG4 Reduction Gearbox Oil Leak

[Fogey]

In fairness it is only the dual clutch gearboxes that have failed in SOME Ford Focus, Hyundai, VW's and a few other related brands and in many cases it was because owners had no idea how to drive them without burning out clutches. I had a Renault Clio RS 200 (hot hatch) for many years with a dual clutch auto and had no issues with it because you need to drive them like a manual car with an auto option and not allow them to 'creep' in traffic or not allow the transmission to hold the car stopped on a hill but use the brakes in the same way you would preserve the clutch on a manual car.
Also there have been very few dramas with torque converter and CVT trannies over the years in ICE vehicles.
I love the MG4 but time will tell whether the 'transmission' will hold up over time.

Yes - you have to "baby", to some extent, the dual-clutch transmission when in traffic - which is another negative (I'm familiar with that, because I run an auto which is similar in that regard - and it's tedious).

And the trouble with torque-converter types - though they can otherwise be very good - is that they're inefficient (and pretty complex, needing precise maintenance). Though the Peugeot/Vauxhall EAT8 is pretty decent. Automated manual 'boxes are OK in some respects, but are nastier to drive than the Dual-clutch types. CVT's are not good to drive either - with sluggish responses - and a record of poor reliability (note: Toyota's misnamed "e-CVT" excepted).

The MG4's simple reduction gearing should be a cause for celebration, and it's turning out just the opposite because of a lousy breather - amplified by MG's seeming reluctance to fix it satisfactorily.

Which is making me have second thoughts about completing the purchase, I have to add.

 

[tsedge]

MG claim the new breather is a fix. We will know in a few weeks if it fixes the problem or not.

In the meantime, I am not going to speculate further.

 

[Fogey]

MG claim the new breather is a fix. We will know in a few weeks if it fixes the problem or not.

In the meantime, I am not going to speculate further.

Yes - I feel fairly confident it'll work, but the trouble is they seem to be saying they're only going to fit it to a few cars - and only after "reduced filling" has been shown not to work (which, seemingly, it doesn't) on those cars.

 

[AndyL61]

Yes - I feel fairly confident it'll work, but the trouble is they seem to be saying they're only going to fit it to a few cars - and only after "reduced filling" has been shown not to work (which, seemingly, it doesn't) on those cars.

IMHO I don't see how some cars are not affected , if oil is coming out of a breather then this is a design fault and as all the cars have the same transmission ( I am assuming this) then I can only see this happening on all cars until the oil level becomes low enough not to reach the breather , which isn't a good thing , as it will be under lubricated. So I think that the "leak" is probably more widespread than MG are saying and that eventually they will have to modify either all cars or at least all cars with the same transmission if there is a difference . Just my thoughts , only expressing an opinion.

 

[Fogey]

IMHO I don't see how some cars are not affected , if oil is coming out of a breather then this is a design fault and as all the cars have the same transmission ( I am assuming this) then I can only see this happening on all cars until the oil level becomes low enough not to reach the breather , which isn't a good thing , as it will be under lubricated. So I think that the "leak" is probably more widespread than MG are saying and that eventually they will have to modify either all cars or at least all cars with the same transmission if there is a difference . Just my thoughts , only expressing an opinion.

Exactly! Those in charge at MG seem to be under the (mistaken) impression that only a few cars are affected - they're clearly not of a technical background. Because of that they're reluctant to do the only sensible thing - which is to arrive at an acceptable fix for the problem, and apply it to all cars. Running out of oil at motorway speeds is no joke!

 

[Scouse plumber]

Maybe the breather valve should be filled with silica gel allow gasses out but keeping liquids in and they are MT ?
just a thought !!

 

[AndyL61]

Maybe the breather valve should be filled with silica gel allow gasses out but keeping liquids in and they are MT ?
just a thought !!

Interesting fix! But my take is a breather is as the name suggests to allow breathing. Oil should not get near it.

 

[wiz043]

Yes - you have to "baby", to some extent, the dual-clutch transmission when in traffic - which is another negative (I'm familiar with that, because I run an auto which is similar in that regard - and it's tedious).

And the trouble with torque-converter types - though they can otherwise be very good - is that they're inefficient (and pretty complex, needing precise maintenance). Though the Peugeot/Vauxhall EAT8 is pretty decent. Automated manual 'boxes are OK in some respects, but are nastier to drive than the Dual-clutch types. CVT's are not good to drive either - with sluggish responses - and a record of poor reliability (note: Toyota's misnamed "e-CVT" excepted).

The MG4's simple reduction gearing should be a cause for celebration, and it's turning out just the opposite because of a lousy breather - amplified by MG's seeming reluctance to fix it satisfactorily.

Which is making me have second thoughts about completing the purchase, I have to add.

I should have added in my comments that torque converter and CVT trannies give little trouble provided they are serviced regularly like everything else and I would imagine the same applies to the MG4's simple reduction gearing.
CVT transmissions have improved markedly in recent times compared to the 'all noise and no go' ones of the past.
I have had experience with all auto transmission types since their inception in my country in the 1960's til now with few issues and look forward to a new experience with the MG4 type when I can eventually get hold of one.

 

[Scouse plumber]

Interesting fix! But my take is a breather is as the name suggests to allow breathing. Oil should not get near it.

in a closed area with oil slingers splashing oil everywhere difficult to avoid oil mist as low as 40 micron however without the desiccant its open to atmosphere hence oil loss
iam probably far away from the true reason just hypostasising
the breather valves are probably supplied by a third part no QC

 

[Hallix73]

Could it also be leakage is due to how hard/fast it has been run. I did read in here someone had got close to 100mph on motorway, higher speed higher gear revs and more splash??

 

[Alb]

It may be exacerbated by speed but I think most owners were seeing the leak after driving at very normal road speeds.

 

[Ian Key]

It could be something as simple as the breather restricting the speed that the warmed air escapes so it comes out under pressure taking the oil particles with it. A larger hole would decrease the speed of the air escaping allowing the oil particles to drop out of the air flow before it escapes.
There again I might be talking ?

 

[Les burrows]

Just popped into the Oil leak poll again now stands at
54 votes
28 now that don’t have the leak that’s up 4 from Friday
21 have a leak but don’t yet know where it’s coming from ( no change )
Les

 

[AndyM]

Still no sign of oil after refill and c.200 mixed country road/motorway miles driven yesterday.

 

[mg4trophy]

Anyone got an update on the cause of this and if mg are taking seriously?

 

[AndyL61]

Still no sign of oil after refill and c.200 mixed country road/motorway miles driven yesterday.

How much oil did they refill it with. 0.7 l ? Which is 22% less than the recomended amount of 0.9 l. I'm hoping that this reduced amount will be sufficent so that we won't have to have any more worries.

 

[Kithmo]

I wonder if there are more than one design of breather ?
I know on the Gen 1 ZS some cars have a plastic breather and some, like mine, have a blanking plug on the drive system.

 

[AndyL61]

I wonder if there are more than one design of breather ?
I know on the Gen 1 ZS some cars have a plastic breather and some, like mine, have a blanking plug on the drive system.

That could be a possibility , would certainly explain why some cars apparently aren't leaking.

 

[SueH]

Well... I have (had?) the problem and took it in last week, explained the situation with the help of a few printed off posts from here and I waited whilst they changed the oil. Presumably at a lower level. There was a very slight misalignment of the undertray but more noticeably a proud screw and washer which I left and marked up with bright yellow gaffer tape so they could see what I mean - the ones further under the car I couldn't inspect. It was commented that there seemed to be a cross-threaded screw, and that now looks ok.

Today I did a 30-40 mile hack down the M27 for an away match with a full load of passengers, and at normal (variable) motorway speeds for the M27.. After playing 80 minutes and a long soak I'm not going to check the oil just now! The check will have to wait for the morning but I'll update here.

 

[FiferMG4]

Well... I have (had?) the problem and took it in last week, explained the situation with the help of a few printed off posts from here and I waited whilst they changed the oil. Presumably at a lower level. There was a very slight misalignment of the undertray but more noticeably a proud screw and washer which I left and marked up with bright yellow gaffer tape so they could see what I mean - the ones further under the car I couldn't inspect. It was commented that there seemed to be a cross-threaded screw, and that now looks ok.

Today I did a 30-40 mile hack down the M27 for an away match with a full load of passengers, and at normal (variable) motorway speeds for the M27.. After playing 80 minutes and a long soak I'm not going to check the oil just now! The check will have to wait for the morning but I'll update here.

?You can report back with good news.