Corrosion timebomb on MG 4 ?

[Macadoodle]

Much like the ZS, the 4 appears to have basically no factory underseal along the sills etc. Had a good look at mine today and its just primer by the looks of it, not even a colour coat like the rest of the body.
One of the worst unprotected water traps is the front subframe where the inner bushes of the track control arms mount.
You can see them clearly if you lift the bonnet, the bolts sit in deep 'cups' and mine were filled deep with salty, gritty road water, barely 300 miles covered I wonder how many winters it will take for your bottom suspension to part company with the rest of the car ?
I cleaned the recesses , dried them, and then soaked the area with waxoyl, avoiding getting any on the rubber.

I think MG cars are a bit like buying half cooked bread you have to finish off yourself at home ?

 

[Spaniard]

Any chance of sharing some photos, please? Just to have some reference to know where to look at.
Thanks

 

[wiz043]

I think MG cars are a bit like buying half cooked bread you have to finish off yourself at home ?

Yep...like some toys you buy with the caption 'some assembly required'.

 

[Tig170]

Much like the ZS, the 4 appears to have basically no factory underseal along the sills etc. Had a good look at mine today and its just primer by the looks of it, not even a colour coat like the rest of the body.
One of the worst unprotected water traps is the front subframe where the inner bushes of the track control arms mount.
You can see them clearly if you lift the bonnet, the bolts sit in deep 'cups' and mine were filled deep with salty, gritty road water, barely 300 miles covered I wonder how many winters it will take for your bottom suspension to part company with the rest of the car ?
I cleaned the recesses , dried them, and then soaked the area with waxoyl, avoiding getting any on the rubber.

I think MG cars are a bit like buying half cooked bread you have to finish off yourself at home ?

Thanks for elucidating, we will be certainly having a look (maybe need the ZG-90 - black ? )

 

[TomLane]

Pop it in writing to your dealership and keep it safe in case there are any issues at a later date. I have taken a screenshot of your comments.

 

[Macadoodle]

Any chance of sharing some photos, please? Just to have some reference to know were to look at.
Thanks

I'll do that once the festivities are over and it's a tad warmer

 

[stevegus]

Neither does my 17 yo Porsche which also has a full plastic undertray like the mg4.

And its absolutely pristine

 

[Elec Car Aust]

Much like the ZS, the 4 appears to have basically no factory underseal along the sills etc. Had a good look at mine today and its just primer by the looks of it, not even a colour coat like the rest of the body.
One of the worst unprotected water traps is the front subframe where the inner bushes of the track control arms mount.
You can see them clearly if you lift the bonnet, the bolts sit in deep 'cups' and mine were filled deep with salty, gritty road water, barely 300 miles covered I wonder how many winters it will take for your bottom suspension to part company with the rest of the car ?
I cleaned the recesses , dried them, and then soaked the area with waxoyl, avoiding getting any on the rubber.

I think MG cars are a bit like buying half cooked bread you have to finish off yourself at home ?

Time will tell but thanks for sharing so 4 owners can keep an eye on it. ?

 

[Macadoodle]

Neither does my 17 yo Porsche which also has a full plastic undertray like the mg4.

And its absolutely pristine

Porsche use no underbody protection apart from a bit of plastic ? ok.
Having owned several VW group cars over the years, all have been extensively treated with a textured underbody coating, galvanizing can only help so much as the winters roll by.
It depends on the conditions you're going to be driving your MG4 in of course, around here the roads are wet for much of the year with a liberal dosing of salt thrown in for at least a couple of months.
The plastic sill covers on the 4 will trap the wet grime behind them IMO, slowly rotting them away.
As soon as the weather improves I'm going to invest in a gallon of clear waxoyl and cover any exposed metal I can access.
I've found wax coatings to be a really good product for rust prevention, they remain flexible so moisture cannot get trapped beneath and can be easily topped up if abraded .

 

[stevegus]

Yeah its very likely galvanised so didnt need underseal. And if id did you cant see it anyway! Can you see anything like a coating in the photo? Pretty much all of the wheel arches are plastic lined too. And suspension and engine mounting are alu alloy that doesnt rust

There is no other obvious coating. Porsche was not owned by VW in 2005 when the car was made


I also have a 2019 VW group Ateca that doesnt seem to be bristling with anti corrosion coating either.

I obviously wasn’t thorough enough in the original answer to satisfy pedants

 

[Cocijo]

Pop it in writing to your dealership and keep it safe in case there are any issues at a later date. I have taken a screenshot of your comments.

I think that you will struggle with MG and their dealerships with anything other than severe (holes) corrosion. And even then it is limited to ‘body panels perforated corrosion from inside to outside.

 

[stevegus]

If the car has been designed to “modern” standards like my 17 yo Porsche with zero mot fails it doesnt need gallons of waxoil and underseal like an old Cortina did.

Most cars use plastic wheel liners and undertrays with minimal use of coatings. Generally every panel is zinc plated too.

Not seeing protective crud on every underside part does not mean its not properly protected.

Any corrosion warranty requires you to PAY for a repair as soon as corrosion is noted and the mfr only pays out on perforation / hole - which is unlikely if you have to repair it at your cost on annual inspection. Read the “small print”

Its rare to see a modern car scrapped due to rust - far more likely to be emissions or crash damage/ costly maintenance

Plus i really cant see an MG4 being 15 yo or so on a second hand market as the battery and tech prob didnt last that long.

 

[Alb]

Besides all that, MG very thoughtfully designed the MG4 to apply a continuous coat of oil to the underside and everybody complained about it so they can't win

 

[Ayoull]

 

[Macadoodle]

Yeah its very likely galvanised so didnt need underseal. And if id did you cant see it anyway! Can you see anything like a coating in the photo? Pretty much all of the wheel arches are plastic lined too. And suspension and engine mounting are alu alloy that doesnt rust

There is no other obvious coating. Porsche was not owned by VW in 2005 when the car was made


I also have a 2019 VW group Ateca that doesnt seem to be bristling with anti corrosion coating either.

I obviously wasn’t thorough enough in the original answer to satisfy pedantsView attachment 14024

Difficult to tell from that pic but i'll accept what you're saying. Each to their own decisions at the end of the day.
If you're on PCP, lease or whatever, sure don't worry about it, if you own the car and plan to keep it.....
Simply can't agree that using galvanized steel and having a quick dip in e coat is sufficient protection for any cars underside in this part of the world though.
I've seen a few pics of the underside of the gen 1 ZS and they're certainly rusting. We have 3 other cars in our household, a 2014 Nissan Leaf , 2015 Seat Leon, and a 10 yr old Toyota Yaris.
All are galvanized but are still coated along the sills etc with factory textured underbody protection.
Sure, they do tend to skip some higher up parts behind the plastic panels to save on cost and weight but I've never seen a modern car with totally exposed sills like the 4.

 

[Macadoodle]

Quite a difference between Leaf and MG4, but then the Leaf is a 'proper' car

 

[Auto Surgeon]

Much like the ZS, the 4 appears to have basically no factory underseal along the sills etc. Had a good look at mine today and its just primer by the looks of it, not even a colour coat like the rest of the body.
One of the worst unprotected water traps is the front subframe where the inner bushes of the track control arms mount.
You can see them clearly if you lift the bonnet, the bolts sit in deep 'cups' and mine were filled deep with salty, gritty road water, barely 300 miles covered I wonder how many winters it will take for your bottom suspension to part company with the rest of the car ?
I cleaned the recesses , dried them, and then soaked the area with waxoyl, avoiding getting any on the rubber.

I think MG cars are a bit like buying half cooked bread you have to finish off yourself at home ?

I'd definitely been keen to see pics of this a soon as poss, I deal with rust on a daily basis & wouldn't want to have to on a new or couple of year old car. Thanks

 

[Macadoodle]

Quality of the pics isn't great sorry, need a new phone with a decent camera !
First pic is looking up at sill, left in primer at factory and totally exposed to road grime from front wheels.
Second is the deep 'cup' that the bottom suspension arm locates in on front subframe. After cleaning and drying the other day, all 4 were filled with salty water again, they're going to rot like hell if not filled with grease or waxoyl

 

[Cocijo]

Yep - you definitely need a new phone…

 

[Spaniard]

Thanks for the photos, but I still have no clue about where do I need to look up.

Would it be possible to take some other photo(s) with a wider vision to get a better idea of where those areas are located?

A guide for dummies, I mean