MG4 Air Conditioning (potential) problem?

[CharlieT]

You could get the AC gas levels checked? At my service they regassed it was they reckoned it was low when done at the factory. I'd complained it seemed excessively noisy, it still worked though.

I don't believe it needs regassing. When it works (over 95% of the time) it works very well. It's just a bit of a lottery whether it'll turn on or not when you get in the car. And nothing I do seems to reset it. Very strange.

 

[ChrisDCB]

As noted on other threads, the battery cooling system shares the A/C pump with the cars interior. When both are required at the same time the automatic battery system will take precedence over the interior and shut it down or reduce its effect until the battery has reached a lower temperature.

Hmmm - not sure about this. When it decides not to work, the compressor does not even try to start up. Might be a gas pressure issue… I am dropping it in to the dealer next week. Will keep you updated.

Try this…
Turn off the a/c before turning off (locking) the car. When restarting the car, wait until the Home Screen has completely settled down then turn on the a/c. Seems good so far… or it might just be magic!

 

[CharlieT]

Try this…
Turn off the a/c before turning off (locking) the car. When restarting the car, wait until the Home Screen has completely settled down then turn on the a/c. Seems good so far… or it might just be magic!

That might work Chris, but I don’t feel I should be needing to turn the a/c off before I get out of the car every time just to ensure it actually turns on again the next time I get in! It’s just yet another thing MG needs to fix, but if it’s a rare fault then I doubt they’ll bother unfortunately.

 

[ChrisDCB]

Sadly - it didn’t work…. Tried the formula this morning and could not get a/c to start. Will see what main dealer has to say.

 

[ChrisDCB]

Well…. I was expecting a faulty pressure sensor or some such but they changed out the complete compressor…

Slightly weird that they had a spare one in stores. Perhaps they are expecting to have to do a few.

 

[CharlieT]

Well…. I was expecting a faulty pressure sensor or some such but they changed out the complete compressor…

Slightly weird that they had a spare one in stores. Perhaps they are expecting to have to do a few.

Interesting. I emailed MG UK about it yesterday and they said it isn’t a known problem, and a dealership will need to investigate. My car isn’t going in until the very end of September unfortunately. I get the distinct impression they aren’t keen on doing warranty work. Another dealership near me said they couldn’t look at it until November!! ??‍

 

[ingobill]

All of a sudden my fans in the air vents are not blowing. All vent sliders are open but not blowing any air. Setting set to max but air blowing. The air vent switch lights up and the mile range reduces by 10 miles but no air or cold air. It went in for a service last week and before that all ok. Came oput of the service and no air blowing. Might just a coincidence. Can advise, anybody?


amendment - Air not blowing went set to Max.

 

[habylab]

All of a sudden my fans in the air vents are not blowing. All vent sliders are open but not blowing any air. Setting set to max but air blowing. The air vent switch lights up and the mile range reduces by 10 miles but no air or cold air. It went in for a service last week and before that all ok. Came oput of the service and no air blowing. Might just a coincidence. Can advise, anybody?


amendment - Air not blowing went set to Max.

Has this been fixed for you?

 

[CharlieT]

An update on my ongoing A/C issue. It’s been a year now since the A/C in my MG4 Trophy started to occasionally not work at all (air blowing but no cooling). Last October (2024) I took it to a local dealership and explained that it usually works fine, but occasionally it doesn’t, so could they please do some problem solving? After leaving the car with them for just a couple of hours they called to say that it’s working today so there’s nothing they can do (). I battled on through the winter with the issue continuing to happen, but this Spring (2025) the problem started occurring increasingly frequently, and the warmer days meant I once again couldn’t bear it. I booked the car into a different dealership and crossed my fingers. After a long wait for the appointment (nearly 3 months) the car eventually went in. Luckily, the A/C didn’t work for them! I was so relieved! But the bad news is, they don’t know why! It was originally meant to be with them for just one day, but that turned to two, and then three, and now they’ve had my car for two weeks and are still going through a trouble shooting process with the technicians at MG UK.

If/when it does get fixed, I’ll let you all know what the issue actually was. In the meantime, I have a newer MG4 as a courtesy car - with working A/C!

 

[Ian Key]

Is the courtesy car's insurance being paid for by the dealer or are you using yours? If yours the dealers usually need it to be covered fully comprehensive so just check your cover. The reason I mention this is mine only covers a courtesy car for one week fully comp before reverting to third party.

And don't expect a speedy result when MG's technicians are involved.

 

[CharlieT]

Is the courtesy car's insurance being paid for by the dealer or are you using yours? If yours the dealers usually need it to be covered fully comprehensive so just check your cover. The reason I mention this is mine only covers a courtesy car for one week fully comp before reverting to third party.

And don't expect a speedy result when MG's technicians are involved.

A great point about insurance. The dealership wanted me to pay a £25 insurance waiver for the courtesy car, but my company insurance happily provides comprehensive cover for any courtesy or hire car while my car is in for service or maintenance. You did make me double check, but it’s all good!

As you say, I don’t think my car will be fixed anytime soon. They were originally going to replace the A/C compressor, but had to get permission from MG UK first as it’s warranty work. The technicians at MG UK asked them to run some different tests first, and then some other ones (on the high voltage system apparently). Each time the dealership does the tests as asked, it takes MG UK days to reply again, hence the time it’s taking. I’m not holding my breath. I just hope it does eventually get fixed once and for all. I’ll be absolutely raging if they give the car back to me only for the problem to reoccur…

 

[PingMeMaybe]

Interesting information CharlieT. My MG4 Luxury (with heatpump) A/C is also acting up. In my case it seems that sometimes when car is left to direct sunlight outside A/C compressor won't start. Blower works fine, just blowing outside air in.

This seems to never occur when starting from cool underground garage. Took car to dealer service center, they didn't find "anything wrong", but we were able to replicate the issue. They are now contacting MG for more information how to proceed.

 

[CharlieT]

Interesting information CharlieT. My MG4 Luxury (with heatpump) A/C is also acting up. In my case it seems that sometimes when car is left to direct sunlight outside A/C compressor won't start. Blower works fine, just blowing outside air in.

This seems to never occur when starting from cool underground garage. Took car to dealer service center, they didn't find "anything wrong", but we were able to replicate the issue. They are now contacting MG for more information how to proceed.

That sounds like it may well be the same issue. The technicians are certainly scratching their heads!