Toyota C-HR 1.8 Hybrid Vibration

[Svein Henrik]

Hello.

I have a 2017 model Toyota C-HR 1.8 Hybrid. It has driven 54 000 kilometers, or 34 000 miles. For three weeks ago, a sudden very small vibration was starting to come from the front. I can feel the vibration through the steering wheel and the floor while driving. It appears when I lift up the gas pedal after acceleration and just barely touch it and hold it when the rpm are as low as it can be while inside the dark green ECO area in the dashboard. It appears in speed from 70 kph to 110 kph and when the engine is warm. I know it is normal to feel a small vibration from the gas engine when it has low rpm, but I can't remember it has been like this before. It looks like it comes when the engine brake kicks in right before it goes to regenerative braking. I have the gear lever at D. I have marked on a picture of the dashboard where I can feel the vibration. But even with cruise control I can feel this vibration from time to time as well when the rpm are low. I am afraid it is the transmission, but I cannot hear any unusual sound from it except the low rpm in the gas engine. I will have the car checked at the nearest Toyota dealer on Thursday 4th. I have Toyota Relax warranty. The vibration does not appear when driving full electric.

I wonder if someone here can help me to figure out what this is.
Best regards Svein

Photo: Toyota

[Haliotis]

Only guessing, but it could be a spark plug not firing properly.  I have taken this view after reading that it does not appear when driving on electric.

[Svein Henrik]

The car don't have any check engine light activated, that should pop up if it was the spark plugs, right? I was checking with a OBD2 reader and could not find any error codes as well.

[Haliotis]

If the EV motors are not linked to the transmission, then I suppose it could be transmission orientated, but would that not be present at any speed - just changing in pitch as the road speed changes?

Coming back to spark plugs - if the vibration is slight and only in certain speed ranges, I wonder how prominent the fault would need to be before any instrument warning is given?

With the difficulty in tracing minor intermittent faults, a process of elimination is often necessary.  Another guess, but it might be worth checking for failure of an engine mounting.  Years ago, I did have a faulty engine mounting due to the rubber bonding failing, and this produced a shake at low engine revs - and quite a bump when stalling point was approached.  Rubber suspension bushes can also cause vibration when the bond between their inner and outer metals fails.

[Svein Henrik]

The vibration is the same between 60 km/h and 100 km/h or higher while the gas engine has low rpm, with my foot slightly on the gas pedal. The vibration is slight but I feel it in the steering wheel. Every time I push the gas pedal to accelerate so the gas engine kicks in I can feel the car is doing a one small shake. And also when parked in P, this small shake is coming when the gas engine starts for heating/charging Battery.

Isn't the electric motors linked to the transmission? I thought they were, but maybe I'm wrong. I will get the mechanic to check the spark plugs and the engine mounts regardless.

[Haliotis]

Hi Svein,  I found this on my browser: https://mag.toyoyta.co.uk - Toyota hybrid - how does it work?  

The normal combustion engine isn’t connected to the transmission, and instead works as a generator to power the electric motors.

You have said that there is no vibration when you are on full electric power so, as there is no mechanical transmission between the engine and the road wheels, I would be inclined to suspect that the fault is linked to the engine.  This brings me back to suggesting engine mountings and spark plugs be a starting point.  The possibility of something attached to the engine could be tapping against other components as the engine moves on its mountings is another thing worth checking.  This, again, puts suspicion on the mountings, as failure here could allow more movement than is normal.

[Svein Henrik]

It seems like the vibration appears only when the gas engine is warm. Does that have something to do with the spark plugs?

[Big_D]

Quite possible. 

[philip42h]

@Svein Henrik I've no real idea why you are experiencing the reported vibration, but this statement simply isn't true:

18 hours ago, Haliotis said:

The normal combustion engine isn’t connected to the transmission, and instead works as a generator to power the electric motors.

You have said that there is no vibration when you are on full electric power so, as there is no mechanical transmission between the engine and the road wheels

The ICE drives the front wheels via the CVT gearbox. It's a bit different and rather clever but there is definitely a drive connection from the engine, via the transmission to the road wheels.

Hopefully, the dealer will be able to shed some light on the issue on Thursday ... 😉

 

 

[Parts-King]

1 hour ago, Svein Henrik said:

It seems like the vibration appears only when the gas engine is warm. Does that have something to do with the spark plugs?

Or faulty injector giving a slight misfire, I have seen that on a number of Hybrid models 

[Haliotis]

2 hours ago, philip42h said:

@Svein Henrik I've no real idea why you are experiencing the reported vibration, but this statement simply isn't true:

The ICE drives the front wheels via the CVT gearbox. It's a bit different and rather clever but there is definitely a drive connection from the engine, via the transmission to the road wheels.

Hopefully, the dealer will be able to shed some light on the issue on Thursday ... 😉

 

 

Sorry if I have misled anyone, but I only stated what I read on the website.  I found it a bit bizarre to think that there was no transmission connection between the engine and the rod wheels, but the explanation did sound plausible.

[TonyHSD]

Slight vibrations in exactly the same circumstances explained by the OP are normal and typical for these cars. If anything more pronounced, it can be from sticking brake callipers slider pins. Brakes are one of the possible reason for that too. A misfire caused by electrical side will store fault code where a misfire by the fuel mixture will not trigger any codes. 👍

Just check tyres pressure and wear pattern and service the brakes. 
Good luck 

[Svein Henrik]

It turns out there was nothing wrong with the car as they could not find any issues. They believed it was maybe dirt or ice inside the rims causing the vibration. Nothing wrong with the transmission or gas engine. The vibration is very slight.

[Jamesae92]

The 1.8 models suffer from egr ports blocking causing a misfire and the 2.0 models suffer from injector faults usually no.3 injector