MG4 EV (air con / fan problem) noise

[Enjoying my MG4]

My wife and I remain very pleased with our MG4 EV. However, we do have a noise problem when the air conditioning unit is switched on. We reported the problem less than four hours after driving away from the MG dealer and they were as helpful as they could be and replaced the air conditioning unit to no avail. The fault continued and seems to be fan related in my opinion (Depending on the speed the air con is working at). We decided not to have it looked at any further at this time. When we returned to our MG dealer for further repairs, we were provided with an identical car that when inspected, had an identical fault. We then asked to look at other MG4 EV’s on the forecourt, only to find the same fault with all five we looked at. Knowing all the others made the same noise when the air con is switched on, we did not want our car to be dismantled any further. We are now going to chase this up on our first EV service in the hope that other people have reported the fault and had it fixed. We are hopeful that MG4 EV’s will have a factory recall at some stage to rectify the fault. It does seem fan (hitting something ) related in my opinion.

For those that are interested and to aid further, I created a video clip of the noise, that has apparently been sent to MG (China). It probably sounds louder than it is, as a mobile phone picks up the sounds very well. Here is the You Tube link.

Summary- If you have this noise and manage to get it fixed, please let us know, so that we can educate our MG dealer to order the correct spares for repairs. Unfortunately, during our last visit, they lost their MG4 EV mechanic, so this was another reason we did not want it looked at any further, at this stage.

Thanks for reading and am pleased to be on board the forum.

 

[PristDean]

Widely reported. Please read the thread below:

MG4 Air-con & Under tray update

Okay, so after travelling afar to put my car in with a reputable dealer, along with my independent engineers report, they have called me just now to explain: 1. The noisy air-con is due to a faulty fan in the system which needs to be replaced. They have put it to MG as the cost far exceeds...

www.mgevs.com

As a note, if they replaced your unit to no avail, the next course of action would to be replace the PAG oil with PAG 100 instead of the PAG 45 they have likely used

 

[Rolfe]

I had a conversation with my dealer about this at the beginning of the week. I had asked them to look at the aircon noise, not because I thought it was excessive, but because others had said they believed the noise should not be there, and I wanted to know if there was anything wrong.

I can't hear anything from inside the cabin, only when I'm outside the car, and even then it's not all that obtrusive or alarming. Just a bit of a soft warble. The first time I heard it I wasn't even sure it was coming from the car, and looked across the road to see if something over there was making the sound.

The dealer asked me if I could hear the sound inside the car. I said no, only outside. I was told that it's normal to hear it a bit from outside, because there isn't any soundproofing to deaden that ssound from the outside. However the soundproofing of the car itself should prevent it being heard in the cabin. The implication was that if you can hear it from inside the car, something is wrong.

 

[Rolfe]

I've just listened to that recording. (Another Radio 3 afficionado, welcome, kindred spirit.) That's the first recording I've heard that gave me any idea what was being described. That is spectacularly worse than my car sounds.

 

[Enjoying my MG4]

Widely reported. Please read the thread below:

MG4 Air-con & Under tray update

Okay, so after travelling afar to put my car in with a reputable dealer, along with my independent engineers report, they have called me just now to explain: 1. The noisy air-con is due to a faulty fan in the system which needs to be replaced. They have put it to MG as the cost far exceeds...

www.mgevs.com

As a note, if they replaced your unit to no avail, the next course of action would to be replace the PAG oil with PAG 100 instead of the PAG 45 they have likely used

Thank you so much for replying. I posted a reply on the thread you provided after posting my thread and then stumbling across it. I am currently researching the problem as much as I can. I am fairly confident that it is not oil related due to the type of noise it is making. The main different with PAG100 and PAG45 would be the velocity (PAG100 being thicker) and what I am hearing does not seem to be oil thickness (viscosity grade) related for a number of reasons. If you listen to the video, in my opinion, I think it is more likely to be fan related (fan hitting something - maybe due to the thickness of a gasket or seal). It is also possible that the replacement air con also had no oil in it, but unlikely given the noise I am hearing. If it was not in warranty and a new car, I would take it apart myself and fix, as I am sure it is any easy fix (oil; gasket or something else). I would be keen to know if your issue gets fixed and what action was taken. I hope all goes well with the fix. I am not keen to have my car taken apart several times, hence me reaching out to forums to see if and how anyone got it fixed before taking it back to the dealership. It remains a great car and I will also follow your post with great interest. Thanks again.

 

[Rolfe]

My feeling is that all or most of the cars are making a relatively slight noise, which I suspect is related to the grade of oil, but which isn't really an issue for most people. And then some cars are making an unholy racket, and that is probably related to a fault with the fan.

 

[PristDean]

Thank you so much for replying. I posted a reply on the thread you provided after posting my thread and then stumbling across it. I am currently researching the problem as much as I can. I am fairly confident that it is not oil related due to the type of noise it is making. The main different with PAG100 and PAG45 would be the velocity (PAG100 being thicker) and what I am hearing does not seem to be oil thickness (viscosity grade) related for a number of reasons. If you listen to the video, in my opinion, I think it is more likely to be fan related (fan hitting something - maybe due to the thickness of a gasket or seal). It is also possible that the replacement air con also had no oil in it, but unlikely given the noise I am hearing. If it was not in warranty and a new car, I would take it apart myself and fix, as I am sure it is any easy fix (oil; gasket or something else). I would be keen to know if your issue gets fixed and what action was taken. I hope all goes well with the fix. I am not keen to have my car taken apart several times, hence me reaching out to forums to see if and how anyone got it fixed before taking it back to the dealership. It remains a great car and I will also follow your post with great interest. Thanks again.

Okay, that's interesting. I had my car inspected by an independent who mentioned the fan too. But the MG technician dismissed that and wants to replace the AC unit. After your findings that lead to me the oil. So three things at play here within the system, oil, unit and fan. Right now then, the fan seems to be the main culprit judging by what you and my independent have found.
This would explain things better, why Rolfe's is much quieter etc.
I'll feedback to my technician tomorrow.

 

[Rolfe]

I have had another thought. If the noise is the fan then it will be present even if the aircon is not switched on. If you have the HVAC set to warm the car, it should be heard just as much as when you're cooling the car. Conversely, if it's the compressor, then you will only hear it when the aircon is turned on and you are cooling the car. I think.

So far as I have noticed, I think I only hear mine when the actual aircon is switched on. I can't swear to that and I'm not going outside right now to check, but it's another thing to consider.

 

[Enjoying my MG4]

I've just listened to that recording. (Another Radio 3 afficionado, welcome, kindred spirit.) That's the first recording I've heard that gave me any idea what was being described. That is spectacularly worse than my car sounds.

I've just listened to that recording. (Another Radio 3 afficionado, welcome, kindred spirit.) That's the first recording I've heard that gave me any idea what was being described. That is spectacularly worse than my car sounds.

Hi Rolfe. Thank you for taking the time to read and listen to the video. My opinion - It's a factory / design fault / flaw that will get rectified at some stage (Factory / recall). What we known so far. I had my air con replaced (I advise against this, as seal's to put it back together (Jun23) are not available and are on back order for many weeks / months. My dealership managed to get non genuine seals / parts to give my car back to me afterwards.

My dealership (mechanic) informed me that their was no oil in the air con unit (Who known if the replacement air con also has no oil in it)

Personal opinion (I could be so wrong), I do not believe its oil (velocity) related, due to my experience in this area. Given the sound the car makes when turning the air con up / down, at this time, I believe it is a fan knocking noise (Speculation – fan hitting metal – maybe due to gasket or oil seal thickness). The air con firing up noise (In the video) is to be expected and only lasts a few seconds.

Personally – I can hear the noise inside the car (When stationary / in traffic) and outside and if I walk away from the car before locking it (And the air con then switches off). It is a definite flaw that I heard on 5 cars at the dealership, when taking it back for further work. I had a frank conversation with the dealership and we both agreed that it was a flaw and that I would take the car away until others reported it and fault found and fixed, as I did not want my car to be the guinea pig in this area. Although it is an acceptable noise (Sounds louder in the You Tube videos), it is still a factory default / flaw or some kind that needs fixing. The continious (assumeing it) fan hitting noise, can not be good for the car long term. On a very positve note - it has a seven year warranty, so it should be sorted out by then!

 

[Deleted member 10041]

Okay, that's interesting. I had my car inspected by an independent who mentioned the fan too. But the MG technician dismissed that and wants to replace the AC unit. After your findings that lead to me the oil. So three things at play here within the system, oil, unit and fan. Right now then, the fan seems to be the main culprit judging by what you and my independent have found.
This would explain things better, why Rolfe's is much quieter etc.
I'll feedback to my technician tomorrow.

Has your fan always been like that or has it got worse over time

 

[Rolfe]

Hi Rolfe. Thank you for taking the time to read and listen to the video. My opinion - It's a factory / design fault / flaw that will get rectified at some stage (Factory / recall). What we known so far. I had my air con replaced (I advise against this, as seal's to put it back together (Jun23) are not available and are on back order for many weeks / months. My dealership managed to get non genuine seals / parts to give my car back to me afterwards.

My dealership (mechanic) informed me that their was no oil in the air con unit (Who known if the replacement air con also has no oil in it)

Personal opinion (I could be so wrong), I do not believe its oil (velocity) related, due to my experience in this area. Given the sound the car makes when turning the air con up / down, at this time, I believe it is a fan knocking noise (Speculation – fan hitting metal – maybe due to gasket or oil seal thickness). The air con firing up noise (In the video) is to be expected and only lasts a few seconds.

Personally – I can hear the noise inside the car (When stationary / in traffic) and outside and if I walk away from the car before locking it (And the air con then switches off). It is a definite flaw that I heard on 5 cars at the dealership, when taking it back for further work. I had a frank conversation with the dealership and we both agreed that it was a flaw and that I would take the car away until others reported it and fault found and fixed, as I did not want my car to be the guinea pig in this area. Although it is an acceptable noise (Sounds louder in the You Tube videos), it is still a factory default / flaw or some kind that needs fixing. The continious (assumeing it) fan hitting noise, can not be good for the car long term. On a very positve note - it has a seven year warranty, so it should be sorted out by then!

This was partly why I mentioned it to my dealer. I wanted to have it on record that I had drawn it to their attention as a possible issue, in case it got worse later.

Can you hear anything when the AC unit is not switched on and the HVAC is only in heating mode?

 

[PristDean]

Has your fan always been like that or has it got worse over time

It sounded bad from the outset. Of course something I didn't test when i bought the car but when the weather heated up, on came the AC and out came the noise, not getting any better and can be heard inside the car.

Really appreciate the input from @Enjoying my MG4 here, this really feels like we are nearing a solution.

 

[Enjoying my MG4]

Has your fan always been like that or has it got worse over time

It been like that straight after picking it up (New car - less than a few hours driving off forecourt). Replacement air con made no difference. The noise remains the same and has not changed since we picked the car up in June 2023. It gets slightly louder (See video - as though fan is moving faster), if the air con is switched on higher.

 

[PristDean]

This was partly why I mentioned it to my dealer. I wanted to have it on record that I had drawn it to their attention as a possible issue, in case it got worse later.

Can you hear anything when the AC unit is not switched on and the HVAC is only in heating mode?

When the AC is switched off in mine, I hear a low varying whistling noise.

 

[Enjoying my MG4]

This was partly why I mentioned it to my dealer. I wanted to have it on record that I had drawn it to their attention as a possible issue, in case it got worse later.

Can you hear anything when the AC unit is not switched on and the HVAC is only in heating mode?

It only happens when air con is switched on. It happens once you hear the air con firing up so to speak. You can hear that in the video. It sounds quiet bad, but in my opinion the firing up is to be expected on any air con, so that noise part is of no concern. It’s the continuous (fan?) knocking noise that’s loud and irritating.

 

[Deleted member 10041]

It sounded bad from the outset. Of course something I didn't test when i bought the car but when the weather heated up, on came the AC and out came the noise, not getting any better and can be heard inside the car.

Really appreciate the input from @Enjoying my MG4 here, this really feels like we are nearing a solution.

Do you think the wrong oil could have been used initially and the now more frequent use is causing the fan to fail, causing the extra noise

 

[Enjoying my MG4]

Do you think the wrong oil could have been used initially and the now more frequent use is causing the fan to fail, causing the extra noise

I have an amount of experience with oils and velocity and do not believe it is oil related at this time due to the type of noise I am hearing (Unless the replacement air con also had no oil in it, which is possible!). I would love to take it apart myself to fix, but it would invalidate my warranty if I do so. The air con was replaced (Not advisable due to seals being on backorder – so you may be without a car for several weeks / months – no idea why they would not include seals in the replacement parts if they were needed - non genuine seals can be found (apparently - they were for our car) if you go down this route!). Unfortunately, I have not been able to find any PDF's or break down diagrams of an MG4 to review further myself at this time. It would be good to understand this area and seals / gasket thicknesses used. Our dealership had great difficulty finding seals to install the new air con and we were nearly without our car for several weeks / months. We were told that prior to the air con being ordered, the video footage I produced was sent to MG to authorise and receive it's replacement. There was no change in the noise (See video) after the air con replacement

 

[Rolfe]

It only happens when air con is switched on. It happens once you hear the air con firing up so to speak. You can hear that in the video. It sounds quiet bad, but in my opinion the firing up is to be expected on any air con, so that noise part is of no concern. It’s the continuous (fan?) knocking noise that’s loud and irritating.

So I'm not actually understanding this. If the heating is on, the fan is on. So if the problem is not there when the heating is on, surely it can't be the fan? Or am I misunderstanding something?

 

[Enjoying my MG4]

So I'm not actually understanding this. If the heating is on, the fan is on. So if the problem is not there when the heating is on, surely it can't be the fan? Or am I misunderstanding something?

Hi Rolfe. It's a very good point. Unfortunately, technology has moved on since my time in this area and I lack the understanding of how an MG4 EV heating works at this time. I was pleasantly surprised when I spoke to the MG4 EV mechanic (Before he left the dealership) and he explained that what I thought may have been a bearing related noise, technology had moved forward in this area and bearings were not used in the manor that I was familiar with anymore and for the MG4 EV and its air con unit. When he listened to the noise, he also thought it was air con related and apparently found that there was no oil in the original air con unit (Identified during replacement). Current summary - If the heating is on, there is no noise. However, once the air con is switched on, after the initial noise (what I will call an understandable air con take off noise - see video 1.11 seconds in), what I can only describe as a fan clicking noise starts (See video) and depending on the temperature setting, depends on the noise. If you listen to the video, when the air con is set to the lowest temperature (look at video time line 0.00 to 0.13 seconds) it sounds like a fan is moving and hitting something very fast. From the time line 0.13 (Moving the temperature setting to 25), it is as though what I can only explain as a fan hitting something at a slower speed, is a more obvious clicking noise. This clicking noise can be heard inside the vehicle (When in stationary traffic if the air con is on) and outside very clearly on at least five (+ mine) MG4 EV’s that I have witnessed at my dealership. Assuming the air con unit was actually replaced, which I have no reason to doubt, given my relationship and discussions with the dealership, I may have either another faulty air con unit or possible a faulty fan (depending on how heat is delivered into the car), caused by something like an incorrect gasket or seal sizing maybe (Depending on how an MG4 EV works in regards to heating the car). I am struggling at finding possible ideas and resolution. Hence the forum for thoughts in this area. Any thoughts and resolution on anyone’s MG4 EV would be most gratefully received. It is also of course possible that the replacement air con unit also has no oil in it. There are reasons I say this which are around cars being built before (warranty) replacement parts are produced, so my replacement air con may have come off another car, which had no oil in the air con unit (yes - clutching at straws now!)

 

[Themist0]

Might be worth checking this is covered by warranty if you leave it til after the first year as I thought the 7 years was only in the battery