[kerbstone]

Update:
Supercharger (compressor) replaced by Mazda dealer. 4 hour job. Part number different to original so assume a modified version.

Drove home by long route to ensure engine well up to temperature, and that supercharger & supercharger clutch as warm as when previously groaning. No groaning heard. So, tentatively, the supercharger replacement seems to have solved the issue, although cannot test extensively at the moment due to lockdown.

The CX-30 is a real pleasure to drive, if this is the only problem to emerge then I will be well pleased.

 

[servlox]

Hi. I'm from the UK and actually own a Skyactiv X equipped Mazda 3 GT Sport Tech. I'm reaching out here because I have this same annoying intermittent 1 second acceleration squeak when the engine is fully warm and been driven for at least 30mins and only started a few months ago when the car had 4000 miles on the it.

I am frustrated as my local dealer where I purchased the car new from in January 2020 is saying its "normal" referring me to Mazda's tech bulletin which states the noises are attributed to the supercharger and are perfectly OK.

I do not agree at all that the noise I have is in anyway a characteristic of normal engine sounds and the fact it is so audible within the cabin when driving is a distraction in itself.

I firmly believe it is the Supercharger issue which as some have already alluded here have eventually been warranty replaced with an updated unit.

The big problem I have is getting a technician to experience the noise as it only appears to occur when on a long drive so its not something that can easily be replicated within a workshop environment.

I feel I am being fobbed off by my dealer and possibly Mazda UK? who are in denial that an issue exists. So I could do with some help from those here that have had the noise and either are in the same position as me or have had the issue sorted. ?

Thank you in advance
Rob

 

[Ronnie]

Record the noise as evidence with a dashcam or phone on a long drive when the engine is warm, that helped some of the German guys.

 

[davey_lad]

Update:
Supercharger (compressor) replaced by Mazda dealer. 4 hour job. Part number different to original so assume a modified version.

Drove home by long route to ensure engine well up to temperature, and that supercharger & supercharger clutch as warm as when previously groaning. No groaning heard. So, tentatively, the supercharger replacement seems to have solved the issue, although cannot test extensively at the moment due to lockdown.

The CX-30 is a real pleasure to drive, if this is the only problem to emerge then I will be well pleased.

Hi kerbstone, Hope you're still around to reply to this

Just came across this thread and your messages.

I've literally just returned home from Mazda dealer after reporting (more than once) noises that seem to fit the description of the super charger issues. I wasn't aware of this problem until the dealer mentioned the "bulletin" which prompted me to start searching around on the forums.

I have another appointment booked in next week where they're going to supply me with a car to see if I can hear the same noises on it - which would almost certainly confirm it as a super charger problem.

I just wondered if you have experienced any more issues since yours was replaced or whether you consider it fixed ? Would be good to know.

For what it's worth, when i first tried to describe the noise to the dealer the best description I could think off was that it sounded a bit like the screech you get when your windscreen wipers move and it's dry 🤷‍♂️.. and it only happened after 30-40 mins of driving. Thankfully was able to reproduce this for the dealer tech to hear.

 

[kerbstone]

For some reason I haven't had notifications that there have been recent questions on this...

Since supercharger replacement I have not had the squeaks/screeches again. But time will tell because mileage is lower following pandemic.

The key to resolution is a good pro-active dealer who has a good relationship with Mazda tech. I understand that Mazda tech insist on receiving a video + audio recording of the vehicle - made by the dealer - to demonstrate the squeaking. It seems to me that comparing with another vehicle won't hack it if that loan vehicle is already displaying the squeak. Try to get your dealer to take ownership of the problem, and make a video.

The bulletin covers other noises, not this "chewbacca" noise which is different. So it's a red herring.

The supercharger ("compressor") noise seemed to appear not just when the engine had got to normal operating temperature, but perhaps 20 minutes beyond that. I assume that the component itself has to get hot before the noise appears. In my case (automatic gearbox), once hot, the noise was easily generated by for example slowing down for a roundabout or traffic lights, then gently applying throttle again (when the irritating squeak then occurred).

My dealer says that they have had a couple of others like mine. But I guess it is fairly rare.

Hope that helps.

 

[davey_lad]

The supercharger ("compressor") noise seemed to appear not just when the engine had got to normal operating temperature, but perhaps 20 minutes beyond that. I assume that the component itself has to get hot before the noise appears. In my case (automatic gearbox), once hot, the noise was easily generated by for example slowing down for a roundabout or traffic lights, then gently applying throttle again (when the irritating squeak then occurred).

My dealer says that they have had a couple of others like mine. But I guess it is fairly rare.

Hope that helps.

Thanks for the reply..

This is exactly the behaviour that I am seeing and I've now had the service manager and his "master technician" sat in the car while I've drove about and they've both heard it, so it is officially acknowledged as an issue - they just stop short of confirming it as the super charger (although the master tech suspects it is). I demonstrated this easily too using exactly the same techniques as you.

Mine is a manual rather than automatic, bought new in July and since I'm working from home my mileage is < 2000 - it's been doing this since day 1 so I'm not sure mileage/age is even a factor.

The fact that this isn't evident on every single car with the super charger, only happens under certain conditions and after a undetermined length of time makes it a ridiculous claim by Mazda that it's "normal"

 

[kerbstone]

You must get them to make a recording and send it to Mazda. It's a warranty issue, the noise is neither normal nor acceptable if it is the same as I had. This engine does make weird noises because of the variable and very high compression etc. So the starting point in many cases is that is that customers aren't used to these noises so over-react. I did my homework on the German forums, I am a pedantic and persuasive old git, and my (exemplary) dealer accepted there was a problem without too much convincing.

I am surprised that it is still apparent on a July-registered car - mine is 10 months older (Sept 2020 reg), and my problem was resolved in Jan 2021. Could be old components used I supposed because of covid production interruptions. I am told that the part numbers for mine were:
OLD - MHBBBR655
NEW - HF012070XF

 

[davey_lad]

You must get them to make a recording and send it to Mazda. It's a warranty issue, the noise is neither normal nor acceptable if it is the same as I had. This engine does make weird noises because of the variable and very high compression etc. So the starting point in many cases is that is that customers aren't used to these noises so over-react. I did my homework on the German forums, I am a pedantic and persuasive old git, and my (exemplary) dealer accepted there was a problem without too much convincing.

I am surprised that it is still apparent on a July-registered car - mine is 10 months older (Sept 2020 reg), and my problem was resolved in Jan 2021. Could be old components used I supposed because of covid production interruptions. I am told that the part numbers for mine were:
OLD - MHBBBR655
NEW - HF012070XF

This is good info to know and something I can go back to my dealer with.

Seems we have a few things in common.. I'm also a pedantic and persuasive old git 😂

 

[servlox]

You must get them to make a recording and send it to Mazda. It's a warranty issue, the noise is neither normal nor acceptable if it is the same as I had. This engine does make weird noises because of the variable and very high compression etc. So the starting point in many cases is that is that customers aren't used to these noises so over-react. I did my homework on the German forums, I am a pedantic and persuasive old git, and my (exemplary) dealer accepted there was a problem without too much convincing.

I am surprised that it is still apparent on a July-registered car - mine is 10 months older (Sept 2020 reg), and my problem was resolved in Jan 2021. Could be old components used I supposed because of covid production interruptions. I am told that the part numbers for mine were:
OLD - MHBBBR655
NEW - HF012070XF

Yes this is the frustration I'm having with my dealer and my Sky X Mazda 3.

The problem with mine is that I guess with only 5000 miles on it since new in Jan 2020 I'm not doing enough miles for it to be there all the time. It definitely seems heat related ? and now with cooler ambient temperatures of the last month or so, my car is refusing to make the noise even after 100+ miles of driving which it was doing quite regularly within 40 miles during the summer months.

Like you say the dealer is insisting that they must experience it for themselves in my car to be able to diagnose it and warranty claim it with Mazda UK. They are not taking my word for it or any evidence I can provide myself or from the internet and in fact keep on insisting that any noises from the Sky X engine are as per the tech bulletin states and will be "Normal" without any engine fault lights or codes tripping.

I am of no doubt this groan like noise under acceleration load is NOT a normal noise whatsoever but until I can get the car to do it to order for their techs, I appear to be stuck with it and all the time the clock is ticking until the warranty expires, After which I fear that's when Mazda will wash their hands of any damage that occurs as a result of this?!

 

[lupineblue]

Could someone give some background on this "supercharger"?

I'm used to the traditional superchargers and turbochargers which are driven by the engine to compress intake air greater than the ambient atmospheric pressure for performance purposes.
What is the supercharger in relation to cylinder deactivation and what does it do?

 

[kerbstone]

SkyActiv X - when the engine starts it runs with conventional spark ignition. Compression ratio about 16:1. Once it warms up it can switch to "Spark Controlled Compression Ignition" mode and it runs at high compression - up to 30:1 so is then very lean. As I understand it, the small compressor/supercharger packs air back in so the fuel mixture can burn again. Runs cool so reduces NoX. So it's a bit like a diesel in the high compression mode. Article here is better than most: https://www.motoringnz.com/news/2020/8/24/the-science-of-spcci-explained

Perhaps a bit too clever.......I think that cylinder deactivation is on the SkyActiv G, not the X but may be corrected.

 

[lupineblue]

SkyActiv X - when the engine starts it runs with conventional spark ignition. Compression ratio about 16:1. Once it warms up it can switch to "Spark Controlled Compression Ignition" mode and it runs at high compression - up to 30:1 so is then very lean. As I understand it, the small compressor/supercharger packs air back in so the fuel mixture can burn again. Runs cool so reduces NoX. So it's a bit like a diesel in the high compression mode. Article here is better than most: https://www.motoringnz.com/news/2020/8/24/the-science-of-spcci-explained

Perhaps a bit too clever.......I think that cylinder deactivation is on the SkyActiv G, not the X but may be corrected.

Well I'll be damned:

> Along with less fuel the engine also requires more air for which the solution is a small displacement, belt-driven ‘‘Roots’’ type supercharger.

Is this just the non-US spec models? I don't think the US gets a 2.0L engine.

 

[kerbstone]

I think you are right - USA spec is SkyActiv G with variable valve timing, all 2.5 litre, 13:1 compression ratio. And no "supercharger". Sadly Mazda don't let us Brits have the 2.5L engine, not in the CX30 anyway.

 

[servlox]

SkyActiv X - when the engine starts it runs with conventional spark ignition. Compression ratio about 16:1. Once it warms up it can switch to "Spark Controlled Compression Ignition" mode and it runs at high compression - up to 30:1 so is then very lean. As I understand it, the small compressor/supercharger packs air back in so the fuel mixture can burn again. Runs cool so reduces NoX. So it's a bit like a diesel in the high compression mode. Article here is better than most: https://www.motoringnz.com/news/2020/8/24/the-science-of-spcci-explained

Perhaps a bit too clever.......I think that cylinder deactivation is on the SkyActiv G, not the X but may be corrected.

Yes cylinder deactivation is only on the G engine. From what I believe the Supercharger/Compressor is as above to pack more air in for the SPCCI cycle and I think in our Mazda's case its electrically operated? unlike most conventional superchargers which are driven from the engine's crankshaft.

The fact that Mazda seem to be treating this acceleration noise issue on the X very defensively at the moment I think suggests they are not confident the noise is coming from the supercharger? I don't know what these units cost to replace? But my guess is that they are very expensive? It seems that so far a number of people have managed to get them replaced while the rest of us are having to prove the noise is not our imagination? It seems so odd Mazda is sort of burying its head in the sand on this one with clearly so many reporting the same odd noise. But it is as though they are still scratching their head on why its making such a noise in the first place? but replaced the supercharger on some cars more as a "beta test" to see if that actually cures the issue before they have a definite solution? I could be absolutely wrong but that's what it feels like to me as surely they would have a tech bulletin to replace the superchargers the moment a customer makes a complaint about the noise?.

 

[kerbstone]

I thought that the "supercharger" is mechanical or belt-driven.

BTW on the CX30 there is also an "Integrated Starter Generator" which is belt driven. I don't know if it's on the Mazda 3 SkyX too, but the ISG was a suspect initially for causing the squeaking noise but then it became obvious that it was the supercharger (the ISG alternatively acts as both generator and electric motor to boost power during gear changes (!) - I think....)

I have always found Mazda very good for dealing with warranty claims.

 

[servlox]

Sorry yes you are right the Supercharger is belt driven. But there is a clutch mechanism in it turning it on and off when its needed and not needed. If I listen closely when I've had the "chewbacca" noise I can swear I can hear a faint click of a mechanism switching in and out? so maybe the noise corresponds with the supercharger clutch? And yes there is an ISG on the 3 as well which is part of the 24v mild hybrid system. Actually the dealer's technician referenced the hybrid system, when saying they couldn't just replace the supercharger on my say so.

 

[servlox]

I thought that the "supercharger" is mechanical or belt-driven.

BTW on the CX30 there is also an "Integrated Starter Generator" which is belt driven. I don't know if it's on the Mazda 3 SkyX too, but the ISG was a suspect initially for causing the squeaking noise but then it became obvious that it was the supercharger (the ISG alternatively acts as both generator and electric motor to boost power during gear changes (!) - I think....)

I have always found Mazda very good for dealing with warranty claims.

Hmm I think Mazda warranty is only as good as there dealers. Unfortunately my local one where I purchased the car from are a dual dealership with Ford being their main priority. I have usually had to fight my corner with warranty issues with my previous two Mazda cars as well as this one. Its a shame but my nearest one to them are another 40 miles away.