Vibrations through 2000rpm

[jamski]

Morning all.

So had my first drive to work this morning, and the MPG is staying around the 45 mark which is what I was expecting, lots of twisty back roads, slowing down to pass, so it's not going to be amazing but better than the 28mpg in my other car.

Anyway, I get a pretty loud vibration at 2000rpm. Once through this it's fine, and changing gears at higher speeds staying above 2000 is fine. There's no hesitation pulling away, it's all very responsive and 'nippy'.

I've just put this down the the 3 cylinder engine, but read another thread about it and no one was mentioning this as a reason.

Can anyone put my mind at rest that this is just normal for the car? Probably doesn't help I'm trying to get the best mpg out of it that I can so keeping the revs low. :)

Thanks,

James.

[jamski]

Been doing more reading and it seems like quite a few complain of this, but can't find a thread with anyone who's solved it! Probably because it's a nature of the beasts, but would be nice if anyone knows for sure. :)

[Guest]

Hi James, as you say, the nature of the beast is the vibration around the 2000 rev mark. It is particularly annoying me at the moment as the mirror vibrates, and the rest of the car feels like it is going to fall apart. However, that small price is easy to dismiss when getting good mpg. Do wish there was a cure though. Wondered if stronger engine mounts would do the job?

[jamski]

Thanks very much. It's very weird. Really seems like it's the exhaust rattling on the heat shield or something like that. May well take it somewhere and see if they can have a look. The wheels need aligning as I have some wheel wobble around 70, but other than that this vibration is the only annoying thing!

[jamski]

So I filled up with VPower last night, and there's a definite improvement with the vibration. Time will tell if it's worth the extra money or not, redex went in again. Will keep this routine for a few tanks and see how it goes.

Not sure my fuelly was 100% accurate as I had to try and work out the details for the day I picked the car up, but think it's about right. Car was showing 44.9mpg, fuelly a little less. @bob809, which kind of driving are you doing to get 57mpg??!!

[Guest]

On 11/05/2016 at 9:06 AM, jamski said:

So I filled up with VPower last night, and there's a definite improvement with the vibration. Time will tell if it's worth the extra money or not, redex went in again. Will keep this routine for a few tanks and see how it goes.

Not sure my fuelly was 100% accurate as I had to try and work out the details for the day I picked the car up, but think it's about right. Car was showing 44.9mpg, fuelly a little less. @bob809, which kind of driving are you doing to get 57mpg??!!

Sorry, James, I could swear I had replied to this already. My wife and I try to drive the same everywhere. Not always easy with traffic and the weather obviously. Just entered my latest fuelly entry and it has gone back up again, this time 60.7mpg. All we do is pay attention to gear changes, drift as much as possible up to lights, actually, drift is the wrong word. Images of an iQ drifting around a track come to mind... Coasting up to lights, trying to time gear changes so less braking done and so on. All little things and we don't always remember to do them. A recent (long) trip to Barmouth and back saw the first 'notch' on the fuel gauge disappear, showing 146.5 miles. Just after I saw it change I checked the Trip A mileage, which I always reset when having topped up the tank. The most I have seen before this was 130 miles, approximately. So, just being more careful when you can with the revs and thinking more ahead about corners, junctions and the like can see better results. Thing is, we are not always in the right frame of mind to drive that way. Not so much discipline. Also, the type of roads varies as much as the traffic on them.

[jamski]

On 5/25/2016 at 8:09 PM, bob809 said:

Sorry, James, I could swear I had replied to this already. My wife and I try to drive the same everywhere. Not always easy with traffic and the weather obviously. Just entered my latest fuelly entry and it has gone back up again, this time 60.7mpg. All we do is pay attention to gear changes, drift as much as possible up to lights, actually, drift is the wrong word. Images of an iQ drifting around a track come to mind... Coasting up to lights, trying to time gear changes so less braking done and so on. All little things and we don't always remember to do them. A recent (long) trip to Barmouth and back saw the first 'notch' on the fuel gauge disappear, showing 146.5 miles. Just after I saw it change I checked the Trip A mileage, which I always reset when having topped up the tank. The most I have seen before this was 130 miles, approximately. So, just being more careful when you can with the revs and thinking more ahead about corners, junctions and the like can see better results. Thing is, we are not always in the right frame of mind to drive that way. Not so much discipline. Also, the type of roads varies as much as the traffic on them.

No probs. :) I got 47 from my second fill up. My aim was to get 45mpg and I'm filling up far less than my previous car and the tank isn't nearly as big, so I'm happy with what I'm getting. :)

[Daveyah2002]

I joined today just to post on the vibration subject on my iQ2 and hopefully let you know it has been sorted or otherwise.

I have had the vibration problem for a couple of years now. Out of warranty 2009 model. Initially sticking 5* fuel reduced it but it has gone on to sound rougher again. Worse in cold weather too. The whole car buzzes at 1900-2000rpm. . I wrote to Toyota Japan, who said they were unaware of the issue and not surprisingly was referred to Toyota UK who said they'd do a back-to-back check with another car but the investigation would be at my expense. None of them claimed to know it was a known problem but that's to be expected.

I didn't bother with the comparison. Waste of time and money as I know it's a common issue.

A couple of weeks later the car has had a (voluntary) recall for an Exhaust manifold issue, Campaign CGG12.

Quote - "Soot deposits may build up and close the gas ports in the exhaust manifold, which may cause knocking and result in lower acceleration"

It appears from the German Toyota club that this was mentioned as the cause of the vibration. I am hoping they are correct. The symptoms would suggest this is likely.

It's in the garage now and I have been told they are replacing the manifold but they broke the oxygen sensor removing it from the old one - no surprises there really as it's a very corrosive area . But they had to back order a new one for July 6th.

I'll let you know once I get the car back.

 

[dash]

Hope the manifold replacement sorts it...

and welcome to the Club !!

 

   Dave

[maartenvanheek]

Most people, including me, suspect the clutch for vibrations. But indeed let's see what the manifold replacement will do.

[dezign-iq]

Hi All,

My first post and a new IQ owner (though both my Dad and Bro have one).

Just following up on this post. I too have the vibrations at the not-so-sweet-spot of 1800 - 2000 RPM. Has anyone ever fixed this. I too have already done lots of reading but never came up with anything conclusive as the root cause.

Any help would be hugely appreciated.

Cheers

2009 IQ 2 1.0

 

 

[jockywocky]

This vibe is caused by 'clutch buzz' which is where the friction damping of the clutch outer decreases with increased mileage due to wear. This leads to the clutch outer (the big friction plate) which is excited by the 120° crank firing interval of the triple, oscillating at a resonance coincidental to the frequency of the firing pulses where, as it's lost its damping the combustion vibration is transmitted into the drive train and ultimately into the engine/gearbox mounts and through drive shafts/suspension and into the vehicle Shell and cabin.

The only solution unfortunately is a replacement clutch assy, the vibe shall still be present but at a much lesser intensity than before. Until Toyota understand how to damp the combustion resonances of their triple over increased mileages through the clutch, the issue shall re-appear after a similar mileage after the clutch change.

You can drive around it by using more rpm or just easing off the throttle a touch as the revs pass through the resonance band but it kind of spoils the drive and may increase your mpg slightly. 

[dezign-iq]

Thanks jockywocky!.. 

Thanks for this - It is exactly the info I was looking for. I suspected it was the clutch but lots of people have been down the EGR valve.

I have adapted my driving to suit and it is more tolerable.. though tricky when going up some hills. I have not long had the car (from a dealer) and although the clutch is not covered by the warranty - I may try and get them to pay for a replacment anyway.

Thanks again...

 

[Daveyah2002]

Sorry for not getting back sooner.

After the Manifold update the car definitely picked up better and this alleviated the vibration a little. Seemed to go through the rev band a little faster/smoother.

However several months on, the car is back to being a painful POS to drive.  There is zero enjoyment driving this car.

Unfortunately the worst of it is also at the lower speed limits, which I am in a lot of the time. I have to drop an extra gear and use more fuel to try and reduce the vibration.

I have already told 2 people that showed an interest in buying one to take it off their list and buy something else and will continue to do so whenever anyone asks.

I'll keep this car until it dies. This is my 5th Toyota and my last.

 

[Kuneha]

This vibration that you speak of, between 1900-200rpm, I experience it also yet strangely mine is the CVT automatic. From what I've read and seen, I believe it is MUCH more pronounced in a manual but I definitely feel this symptom to an extent. I usually notice it because the CVT likes to sit around 1900-2000rpm when setting off and for some annoying reason this rpm range creates a resonance that seems to make a buzzing noise. I'm not sure where the noise comes from as I have prodded everything around the car to attempt to locate it. I've changed the water pump, both aux' belts, inspected the other pulleys, checked all heat shielding from the back end of the car to the front, poked and prodded everything in the engine may and interior.

I'm always skeptical with 3 cylinder engines as they're naturally unbalanced and I would have to say the 1KR-FE isn't one of my favourites.

[jockywocky]

Hi Kuneha,

From what I've read, the toyota cvt uses a torque converter plus a lock up clutch where, depending on the rpm/load/throttle position I would imagine the point of lock up would be variable. As the key issue is damping, there may be an amount of viscous damping provided by the torque converter, there may be none at all depending on how this lock up clutch works and, as the clutch is locked the same theory applies as a standard manual gearbox where it still requires an amount of damping to reduce combustion resonance vibration. I suspect that a similar design of clutch damping is used for the lock up clutch of the CVT transmission to the manual where the damping has degraded over mileage same as the manual ones hence you are feeling some vibe. There may be an additional damping effect with a CVT trans due to the metal belt tension absorbing some of the vibe before it reaches the chassis hence the reason it does not seem so harsh on your CVT IQ. 

3 cyl engines are not that difficult to balance, with a 120° crank there is a rocking couple to take care of with a 1:1 balance shaft, the problem lies with combustion damping where a lot of r&d is required to keep a smooth drive train. Through design simulations you can predict and account for the amount of vibe (at rotational & combustion orders) although, until substantial engine rig testing plus test mileage has been covered whilst monitoring any changes in NVH using FFT analysis for both noise and vibration reaching the driver you never know if design shall correlate to predictions over the vehicle life cycle. A constant challenge to the design and NVH engineers!

[Cyker]

It might be worth checking the engine mounts - I'm wondering if one of them has become slightly loose or the rubber has perished or something?

3 cylinders tend to be a bit rough at lower RPMs but I find they're smoother than 4 cylinders at higher RPMs, esp. smaller ones like the 1.0 VVTi (And that one loves to be revved!).

@jocky: The newer Toyota CVT is purely belt-driven AFAIK; Where did you see the bit about it having a torque converter? The only modern locking torque converters I know of in Toyota cars is in the lovely GT86 auto 
 

[jockywocky]

Hi Cyker, 

Looked at toyotas cvt transmission delelopment history where I gives the IQ 1.0 as having a K41A - CVT where I found a great pfdf file explaining how it works:

' https://www.google.lk/url?sa=t&source=web&rct=j&url=http://webpages.charter.net/scott.mcclure/Yaris/K41A%20CVT/K41A%20-%20CVT%20-%20General%20Info.pdf&ved=0ahUKEwie9qi40o7RAhXIqI8KHY3KAJAQFggYMAA&usg=AFQjCNGkYdi-_NhAr5Uw4OGivbdKwjtIZQ'

In this file is states there is a torque converter with a low speed lock up clutch although it does not show the rpm where the lock up engages, interesting stuff this vibration issue!  😃

[Cyker]

Oooh that's very cool :)