Undertray/wheel arch plastic damage

[craigupnorth]

When I picked up my car it had a small undertray bulge. I knew it was a common issue, but I looked at it with the dealer, all the bolts were securely fastened, and it wasnt a big bulge (maybe a finger width deep), so decided to simply accept it, and monitor it in case it got worse.
I checked it over the weekend (two months in) - the bulge has basically disappeared. It seems like its settled over time, all looks good now.

 

[Rolfe]

Lucky you!

 

[siteguru]

Must be that all the exercise has flattened its stomach.

 

[NLMGSAN]

When I picked up my car it had a small undertray bulge. I knew it was a common issue, but I looked at it with the dealer, all the bolts were securely fastened, and it wasnt a big bulge (maybe a finger width deep), so decided to simply accept it, and monitor it in case it got worse.
I checked it over the weekend (two months in) - the bulge has basically disappeared. It seems like its settled over time, all looks good now.

How can this disappear?

 

[Tuareg]

Maybe some shrinkage over time which tightens up the panel.

 

[NLMGSAN]

Plastic doesn't shrink?

 

[Ian Key]

Perhaps the colder weather has made it shrink. It might grow again when it gets warmer....

...the undertray.

 

[NLMGSAN]

Ian, I would love to believe you but even that means the real problem still remains: poor manufacturing quality.
Underneath each car air will flow. Some cars now drive around 'with their mouths wide open'....?

 

[ESteve]

Hi everyone,

Yesterday we went partially through some standing water at the side of the road. A puddle a couple of inches deep at most, not fast and not particularly splashy or anything! It's a puddle that we wouldn't have thought twice about before. I heard a cracking sound under the passenger side. A piece of the wheel arch plastic liner had snapped off along with a small chunk out the rear part of the plastic undertray.

My Dad has done a spot of hole drilling, cable tying and duct taping to stop anything flapping while we get it fixed. However we were both a bit taken aback at the flimsiness of the plastic and one of the bolts into the metal was barely in and won't fully tighten. Also the front part of the undertray has a bulge which I now see is quite common.

I'm waiting on the garage to call me back about this repair. I was originally thinking we were just really unlucky, but having seen the quality, the loose screw and bulge I'm wondering if this was just waiting to happen. Is it worth getting the garage to replace the bulging front part on warranty I wonder.

Anyway, posted mostly for information... The undertray and plastic arch are flimsy so don't touch any puddles! And if you haven't looked under your car, check it's actually all in tight as I suspect mine wasn't right in the first place.

I have the same problem. Had passenger wheel arch liner replaced last year and have now found both sides are flapping around. MG are not willing to repair under warranty. Basically the car is not fit for the purpose it was sold for i.e normal driving in normal conditions. I will take this up with MG directly and let you know if I have any success

 

[Rolfe]

Welcome to the forum, @ESteve, I'm only sorry it's with such a sorry tale. Please keep us posted on how you get on with MG - some people have had satisfaction.

Please also post about your experience in the MG5 forum, in case members there have experienced similar.

 

[siteguru]

Interestingly, in the James & Kate video posted elsewhere today, James noticed that one of the wheel arch liner fasteners was missing on his nearside rear liner.

 

[FrancisM]

Someone asked about the MG4 and got an answer which more or less resolved to 11 inches. Just under half way up the wheel, and level with the door sill. (I think they don't certify that the door seals will keep standing water out.)



Have you seen the video of that car that went into three feet of water and actually floated for a bit before making it out? 2 minutes 7 seconds on here. The driver was mad - just barrelled into the water as if he hadn't even seen it.



View attachment 21254

That MG4 floating along before continuing is amazing. But risking a 400V battery in floodwater can't be a good idea!

 

[Rolfe]

Oh, he was an absolute idiot. But he got away with it. (I don't think there's any danger from the battery as such, from 30 seconds in fresh water. If there were, we couldn't drive these cars in the rain!)

 

[tsedge]

The batteries are extremely well sealed, you are far better off in an EV with water. I am not saying there's no risk (probably most likely at the HV connectors), but a brief 'swim' is generally survivable.

You are more likely to hurt other components, such as suspension or lower body corrosion, or water getting into the gearbox.

That said, I am never going to drive any car through more than a few inches of water. It is never worth the risk.

 

[Tig170]

The batteries are extremely well sealed, you are far better off in an EV with water. I am not saying there's no risk (probably most likely at the HV connectors), but a brief 'swim' is generally survivable.

You are more likely to hurt other components, such as suspension or lower body corrosion, or water getting into the gearbox.

That said, I am never going to drive any car through more than a few inches of water. It is never worth the risk.

True: but do bear in mind that seals can fail (this one was out of warranty - due to mileage) - enjoy.

 

[welshwizard]

11 and a half months later my under tray front right side is hanging off. Took a look and the plastic that the tray is screwed to has broken and left a hole. Surely I'm covered?

 

[stevegus]

Somehow in my 21 months old 15k miles car, nothing has broken or fallen off yet.

Software based issues tho……