MG4 Undertray dip/bulge

[kin]

Most manufacturers do this now, but not all, especially with software. It is a shame but seems to be becoming the norm.

I agree, software is the main issue with most cars nowadays.

 

[Kithmo]

Most manufacturers do this now, but not all, especially with software. It is a shame but seems to be becoming the norm.

They've always done it, ever since cars were first mass produced.

 

[tsedge]

I just put mine on ramps to have a better look, it looks like the tray has distorted post production. In that if you push up on it it does go flat, but wont stay due to the warping of the untertray. The undertray is quite flimsy, with no support / strength ribs (which is normal on combustion engine undertrays). So in my humble opinion, the part which the rear under tray attaches to (its touching it, if you push it flat) gets hot. The other thing that I noticed was that the 4 x 10mm hex bolts (with 25mm washers on), were quite loose (just over hand tight) - which didn't seem right - attached is a picture taken inside the undertray from the left rear wheel towards the right front, yellow circled is the offending (in my opinion) heat source, causing the distortion??

This is really helpful, thanks. Yes, others have reported loose bolts, which are inexcusable. I wonder though if they are loosening due to the poor design of the tray.

Is there a obvious point an extra fastener or two can be added to stop the drop?

 

[jamesc83]

I just put mine on ramps to have a better look, it looks like the tray has distorted post production. In that if you push up on it it does go flat, but wont stay due to the warping of the untertray. The undertray is quite flimsy, with no support / strength ribs (which is normal on combustion engine undertrays). So in my humble opinion, the part which the rear under tray attaches to (its touching it, if you push it flat) gets hot. The other thing that I noticed was that the 4 x 10mm hex bolts (with 25mm washers on), were quite loose (just over hand tight) - which didn't seem right - attached is a picture taken inside the undertray from the left rear wheel towards the right front, yellow circled is the offending (in my opinion) heat source, causing the distortion??

I wondered if it was heat related yesterday. My gap seemed a bit smaller having sat on the drive overnight. But it was also refitted by the dealer I went to when I was away (the dealer that at the time thought it was normal)

 

[jamesc83]

@Tig170 are you booked in for it to be looked at and then referred to MG. Just curious being same dealer ?

 

[Tig170]

@Tig170 are you booked in for it to be looked at and then referred to MG. Just curious being same dealer ?

@jamesc83 not yet! (pretty hectic for the next few weeks!) - I just wanted to see if mine was leaking (nothing yet), and what were the implications of a warped undertray - attached is the undertray off my VW - which is contoured, strengthened and has some sound (heat?) proofing material on the underside, my feeling is that MG will have to do a bit of a redesign on this element as the current flat / flimsy one isn’t up to standard.

 

[jamesc83]

@jamesc83 not yet! (pretty hectic for the next few weeks!) - I just wanted to see if mine was leaking (nothing yet), and what were the implications of a warped undertray - attached is the undertray off my VW - which is contoured, strengthened and has some sound (heat?) proofing material on the underside, my feeling is that MG will have to do a bit of a redesign on this element as the current flat / flimsy one isn’t up to standard.

Yes you’re probably right, fair enough I’ll let you know what they say to me when I go in.

 

[shaunuk]

Am I winning for lowest car ? I know in my 20s having a lowered car was cool.

 

[AndyM]

 

[Lovemyev]

I wonder though if they are loosening due to the poor design of the tray.

I am thinking along the same lines to be honest.
I just wonder if the bulging is caused because the pick up holes in the under tray, are misaligned with the threaded holes produced in the body shell ?.
Two incorrectly pitched holes in the tray, will cause the tray to buckle and distort between them two points.
My guess would be that these under trays will be one of the last things to be fitted before the car touches the ground.
The time allowed to fit these trays in the factory, will be fairly short and the bolts will be torqued up with nut runner.
If the holes do not 100% align correctly straight away, there will be little time to spend trying to achieve the misaligned bolts.
Maybe this is why people are finding some of their bolts left loose ?.
There has been an attempt to get all of the bolts installed first, then double back and torque all of the fasteners.
The operator may have simply run out of time to complete the tasks.
The issue should have been flagged up and then reworked in a rectification area, if this was the case.

 

[PCR]

seems very interesting wish I could understand Spanish.

 

[Rip Van]

seems very interesting wish I could understand Spanish.

Some clever person might be able to overdub in english? That would be very interesting!

 

[WonkoTheSaneUK]

seems very interesting wish I could understand Spanish.

Some clever person might be able to overdub in english? That would be very interesting!

1. Click "Watch on Youtube"
2. Click on closed captions (Box with lines & dots lower right)
3. Click on settings (cog)
4. Click on "Subtitles/CC" and select "Auto Translate"
5. Select "English"
6. Watch subtitled video

 

[siteguru]

1. Click "Watch on Youtube"
2. Click on closed captions (Box with lines & dots lower right)
3. Click on settings (cog)
4. Click on "Subtitles/CC" and select "Auto Translate"
5. Select "English"
6. Watch subtitled video

Some interesting auto-translation (potato?) ? but generally good enough to understand what's being said.

 

[Archev]

My 1st car was a 1963 classic tartan red ( white roof ) Mini, fitted with an engine transplanted from an Austin 1100.
I had not even passed my driving test at this point.
It was one of the nine classic Mini's I once owned over the years.

Lovely- I once had a superb wee 850 minivan which became much more superber when an eleven hundred power plant was added.
(Note - the word “ power” above is subjective but the low end torque was sublime - especially when towing an 8 x 4 foot trailer )

 

[jamesc83]

Cars been in today. Garage agree with heat theory, but it just depends how quickly MG do anything. I'm wondering if they'll start putting a redesigned one on newer models at some point, at which point it will be possible to get ours replaced. Said as much to dealer.

 

[beefyj]

Mine being worked on at the moment, my mobile is pinging away with notifications!

 

[jamesc83]

Mine being worked on at the moment, my mobile is pinging away with notifications!

What type of notifications?

 

[siteguru]

I imagine notifications from the iSmart app.

 

[jamesc83]

I imagine notifications from the iSmart app.

Probably. Mines never sent me push notifications yet. Guess that’s probably a good thing though