Loud intermittent engine noise

[Maxi9]

Hi, can anyone help with a problem I have with a 2070 2.0 corolla please.

I have only had the car 4 weeks and for the first 3 it was a delight to drive. At low speed, the only time I could really tell the petrol engine was running was by looking at the Rev Counter. Over the last week I have noticed a loud noise which comes and goes. At first I thought it was the radiator cooling fans cutting in but this noise appears even when the car has stood over night and has driven less than 100 yards. Yesterday I drove about 40 miles with no problems, mostly town type driving, then this throaty noise started, rising and falling as I accelerated but after about half a mile it stopped and I was back to quiet. Dont want to go direct to Dealer as in the past when I have had problems, the service department say, "We need the car until it does it for us" as though I am making up problems !!!!.  Any ideas would be much appreciated. Thank You.

[Catlover]

So, you get this throaty noise when you accelerate, that eases off when you take your foot of the throttle.  If that is it, then it’s a characteristic of a Toyota hybrid. My Prius does it, the wife’s Auris hybrid does it.  Accelerate and the engine sort of revs more then the movement of the car. You could compare it to a slipping clutch, if you ever driven a car with a slipping clutch, what happens is you Put your foot down to accelerate and engine revs are much higher then the movement of the car.               
Having a Toyota hybrid for the first time is a learning exercise. There are simple techniques that can be used to get extra economy. A lot can be learned by going on You Tube and looking at videos, usually Prius, usually from USA, on how to drive a Toyota hybrid. Once you “get in to it” you will find you can be more relaxed and enjoy the smoothness of driving a Toyota hybrid.         
Did you know how and when you can “force” your hybrid to run on just electric. The onboard computer does a marvellous job but in certain circumstances, which the driver can create, you can get more from the system.  All in the YTube videos, plus very helpful tips on here.
 

[FROSTYBALLS]

If this happens at low speed (up to 12mph) on electric power and varies according to speed, it is probably the Acoustic Vehicle Alert System - which generates noise to warn pedestrians, especially those with visual impairments, that a vehicle is approaching.

As regards the dealer saying that they need the fault to be present when they have the car, unless fault codes are produced or they can hear/see the problem, they may not be able to identify the issue.

[Maxi9]

Thanks for the replies, this "noise" didnt appear for the first 3 weeks I had the car, it is so loud I would have heard it earlier, not sure about the speed but pretty sure I was doing over 12mph yesterday when it happened. As I said, it is intermittent, happens some days and not others on the same route.

 

[TonyHSD]

3 hours ago, Maxi9 said:

Thanks for the replies, this "noise" didnt appear for the first 3 weeks I had the car, it is so loud I would have heard it earlier, not sure about the speed but pretty sure I was doing over 12mph yesterday when it happened. As I said, it is intermittent, happens some days and not others on the same route.

 

Hi, 

I think best if you can record a video and share with us, it might be something usual for the car but can also be something wrong  and may require some attention from a dealer. Toyota hybrids are different from any other cars as mentioned and does have different noises and behaviour. Have you checked all storage compartments for any loose stuff that can eventually rattling and cause the issues that you described? 
Regards 

[Cyker]

Yeah, I think some recording is needed; If it was the Mk4 Yaris I'd suspect the engine, as the Mk4's engine is loud AF, but if the Corolla is anything like the Auris the engine shouldn't be that loud unless you're pushing it...

 

[TonyHSD]

3 minutes ago, Cyker said:

Yeah, I think some recording is needed; If it was the Mk4 Yaris I'd suspect the engine, as the Mk4's engine is loud AF, but if the Corolla is anything like the Auris the engine shouldn't be that loud unless you're pushing it...

 

The 2.0 Corolla is louder than 1.8 and Auris since it has direct injection in addition to the port injection. Both latest Yaris and Corolla has very similar engines, one is 3 cylinder and the other is 4. These are the latest by Toyota , more information here. 👍https://en.wikipedia.org/wiki/Toyota_Dynamic_Force_engine

 

[Cyker]

I must admit I don't think I've heard the new 2.0 in action yet, but the 1.8 definitely sounds a lot smoother than the 1.5 I have. Doesn't have the same growl for sure. That imbalance in the 3-pot just naturally makes it much noisier and shaky than the 4-cylinders I suspect.

[TonyHSD]

Just now, Cyker said:

I must admit I don't think I've heard the new 2.0 in action yet, but the 1.8 definitely sounds a lot smoother than the 1.5 I have. Doesn't have the same growl for sure. That imbalance in the 3-pot just naturally makes it much noisier and shaky than the 4-cylinders I suspect.

That’s right, the 3 cylinder engines always sounds like hairdryer or lawnmower but many people like it 👍🚗

[Cyker]

Yeah, I must admit it gives me fond memories of the diesel clatter of my old D4D at low RPM 

And like the Aygo it has the weird property that it sounds smoother the faster it revs (The D4D definitely did not do that - The vibrations got quite alarming if you took it north of 3500rpm unless you were using V-Power diesel!!)

 

[Maxi9]

Again, thanks for the help so far. My previous car was a RAV4 so I understand the relationship between the engine revs and the speed of the car. What I sometimes hear now, is not the CVT gearbox. Nothing loose in the car that could cause a rattle, what I hear is a throaty roar when the petrol engine is working and can happen when it is cold or hot but does not happen all the time.

[StreetHawk]

Could it just be the car holding the revs higher to charge the hybrid Battery when it gets low? 

[TonyHSD]

1 hour ago, Maxi9 said:

Again, thanks for the help so far. My previous car was a RAV4 so I understand the relationship between the engine revs and the speed of the car. What I sometimes hear now, is not the CVT gearbox. Nothing loose in the car that could cause a rattle, what I hear is a throaty roar when the petrol engine is working and can happen when it is cold or hot but does not happen all the time.

Ahh, ok then. Toyota internal combustion engines has different cycles of work and depends on the load and what ice is needed to do may sound differently, more throaty or smoothie whether is charging the Battery, propel the car or just in heat up cycles or any combination in between all above. Switch between Atkinson and Otto cycles. There is also VVTI on both intake and exhaust camshafts. Since your one is 2.0 dynamic force engine has direct and port injection and so the difference in sound might be more pronounced than just the previous 1.8 hybrid engine. This is only my theory and not necessarily been true, just make sense to me. My Corolla experience is very limited and only for a short while in 2.0 GR hatch and noticed immediately noisier engine than my auris while engine was running and drivers door was opened. 

 

[Maxi9]

Thank You StreetHawk and TonyHSD, both of what you say makes sense to me, will keep and eye on things over the next couple of weeks and try to tie it down more as to when it happens. 

[Rambler56]

My TS engine/exhaust 'growls' when I'm accelerating fairly hard which is not very often unless I'm getting up to motorway speed on the joining slip, it is pretty quiet and refined in nearly all other driving situations.  The YouTube 'glide and coast' videos show you how to get the smoothest (and most economical) ride out of the hybrid.

[Sohrab Gulam]

Hi, I am a new corolla owner. I have the 2019 2.0 corolla and I'm really happy with it so far.

However, I have noticed this intermittent loud engine noise which does go away after a minute or two. I have taken to the local dealership and they couldn't find a fault. Is this normal? I'm guessing it charges the Battery when this happens or is it a fault that needs to be looked at?

I appreciate any comments on this :)

Sohrab

[TonyHSD]

4 hours ago, Sohrab Gulam said:

Hi, I am a new corolla owner. I have the 2019 2.0 corolla and I'm really happy with it so far.

However, I have noticed this intermittent loud engine noise which does go away after a minute or two. I have taken to the local dealership and they couldn't find a fault. Is this normal? I'm guessing it charges the battery when this happens or is it a fault that needs to be looked at?

I appreciate any comments on this 🙂

Sohrab

Hi, 

very likely to be normal. The op hasn’t returned to comment on the issue now over a year later, perhaps he found no further problems. If you can record your noises that you think might be something wrong and they sound strange to you, here there are many 2.0 hybrids owners that can confirm if theirs does the same or it’s a fault indeed. 

[Sohrab Gulam]

Thank you, it will be hard to catch on a video, basically the tone of the engine just gets louder sometimes, and the arrow shows energy going towards the Battery from the engine. So I'm guessing it's charging but I have no idea 

[TonyHSD]

27 minutes ago, Sohrab Gulam said:

Thank you, it will be hard to catch on a video, basically the tone of the engine just gets louder sometimes, and the arrow shows energy going towards the battery from the engine. So I'm guessing it's charging but I have no idea 

I think it’s normal., when the engine is charging the Battery while stationary or at slow speeds can significantly change its tone and rpm. The motor generator is powerful and requires a lot of energy from the engine to rotates and create electricity, the lower the Battery is the louder the engine it will be. It is intermittent because sometimes the engine is running and charging the Battery but the battery is at higher state of charge and does not require as much energy as when it’s low. 

[forkingabout]

10 hours ago, Sohrab Gulam said:

Thank you, it will be hard to catch on a video, basically the tone of the engine just gets louder sometimes, and the arrow shows energy going towards the battery from the engine. So I'm guessing it's charging but I have no idea 

The 2 litre engine fitted to your Corolla has both port & direct fuel injection systems fitted - Toyota D-4S

It can use either system individually or both systems at the same time, the direct injection fuel pump under the bonnet is loud in operation ( it's just the way they all are ) - it's highly likely this is the intermittent noise you are hearing - you will only hear the noise while the engine decides to run the direct fuel injection system.

[Sohrab Gulam]

Here you can hear the noise. It quietens down after the video ends which I wasn't able to get.

 

But thank you for the comments, atleast I know there is nothing wrong with the car! 

[Popama]

As an owner of a 2 litre engine myself I would opine that the recording is of the Battery charging engine cycle ( which you indicated earlier you also assumed ).
The engine noise is higher during these short cycles as the engine mode is meant to consume the least amount of fuel for the limited production of electricity.
The same engine RPM sounds different when traveling as the engine is engaged in a ”normal” running cycle and it uses electricity to compensate the power demand or to harvest the excess power of the engine.

In short it is normal engine noise.

[Sohrab Gulam]

Thank you! 

[Sohrab Gulam]

Is it normal for the Battery to always be half full, never seems to go any higher 

[TonyHSD]

Just now, Sohrab Gulam said:

Is it normal for the battery to always be half full, never seems to go any higher 

Hi,

yes it’s normal and this is how the system maintains the Battery soc (state of charge). Sometimes after you drive on a long downhill you may see your Battery is full but the engine is running at higher rpm, don’t worry, this is also normal and happens because the system uses the engine to discharge the Battery to more appropriate levels, which are between 40-80%.