Vibration

Stuart Aspey · February 26, 2021

In the passed couple of weeks, I've noticed something that I can't quite put my finger on (was noticed before wheels were done and after) I thought it could've been a balancing issue.

When driving and almost always when approaching 70mph, I get a vibration, but it isn't constant. Nothing major (the car is going yo Lexus this afternoon) that I thought could be wheelbearings, but there is no noise when checked at standstill (and rotating the wheels)

A friend mentioned it could be the clutch/gearbox, but wasn't sure if the CVT gearbox utilised a clutch in the common manner standard gearboxes do.

The other sensation that sometimes comes in with the vibration is like the car is driving on flat tyres, like the bumps on the road are suddenly amplified in feel through the steering wheel, but then this goes away sometimes as I turn a corner or just after a distance of travel. I wonder if this could be a Bush or joint failing. Again, it's not constant which is annoying me. Lol

ColinBarber · February 26, 2021

21 minutes ago, Stuart Aspey said:

A friend mentioned it could be the clutch/gearbox, but wasn't sure if the CVT gearbox utilised a clutch in the common manner standard gearboxes do.

It doesn't.

There is a resonance issue on the IS300h when the engine is running at around 1,300 rpm. I was able to produce it in my 300h, but I only ever got it at around 50 mph under slight engine load (going up a slight incline where I had to just press the throttle a tiny bit more to maintain speed). Any change in speed or throttle would stop it so I never bothered to get the 'fix' installed - which doesn't completely cure it anyway. Not sure what Lexus would charge to install it on a vehicle out of warranty - there was a TSB but only for owners that noticed and complained of the issue would get it fixed under warranty.

I imagine a redesign of some components fixed this on later models, I've not heard of anyone complain of this on a 2016+ vehicle. Most people that have complained of this where in Europe, not sure if road surfaces or being left hand drive made the issue more apparent.

Brechin Slate · February 26, 2021

3 hours ago, Stuart Aspey said:

The other sensation that sometimes comes in with the vibration is like the car is driving on flat tyres

I had this on my IS250 last year. I was particularly concerned when it happened on a perfectly smooth and flat bit of newly laid motorway. Someone on this forum suggested that it might be a flat spot on one or more tyres, sure enough when the time came to change them it completely disappeared. I hope it's something as simple for you.

Brechin Slate · February 26, 2021

Might not be related but worth a look

Stuart Aspey · February 26, 2021

Cheers guys, so there is the possibly that bad or cheap tyres could be the cause....? Currently at Lexus and the technician has taken the car out for a spin. So we might have some more opinions coming back in due corse.

Stuart Aspey · February 26, 2021

Right. As a first time problem (at least to be reported by me) they are looking at wheel balancing as being the cause at this point but will re-evaluate if the problem persists.

Smokey smell was a piece of plastic lodged against exhaust.....

Brechin Slate · February 26, 2021

2 hours ago, Stuart Aspey said:

Smokey smell was a piece of plastic lodged against exhaust.....

At least a cheap fix!

Stuart Aspey · March 18, 2021

Soo.. Its back... Almost unnoticeable until 60mph-80mph. Its there when pressing the accelerator and when not. Its there when braking and when not. Its there over different road surfaces. Its there a little in the steering wheel, but doesn't feel like the front of the car. Its more pronounced in the seat, if that makes sense? Could it be a wheel bearing or could it be the active damper issue that was mentioned in the other thread? Car is going back in tomorrow.

Could it be cheap tyres that are sitting for 5 days out of 7.....

paulrnx · March 19, 2021

Based on my past experiences of similar with both an A4 and a Jaguar XF, my money is on tyres that have worn slightly out of round at a point in their life. In both of my cases, replacing tyres fixed it. If you’re feeling it through seat of the pants I’d say it’s the rears. If you’re feeling it through the steering I’d say it’s the fronts. You could try swapping rears and fronts around to see if the symptoms move. A decent dealership or a professional tyre outfit should be able to run some tests to see if one or more of the tyres have worn out of round. Balancing an out of round tyre makes very little difference because the tyre circumference is no longer completely circular. Hope this helps a bit.

Brechin Slate · March 19, 2021

10 hours ago, Stuart Aspey said:

Car is going back in tomorrow

If it's going back in to be checked then you can just wait to see what they say or run a few simple tests at home. If it were me I'd jack up each wheel in turn spin them and check for any noise then rig up a pointer that's not quite touching the tyre and rotate again noticing any change in gap between the fixed pointer and rotating tyre. Hope that makes sense!

Stuart Aspey · March 19, 2021

@paulrnx

@Brechin Slate

Thank you both for your comments and suggestions. The mechanic brought me to the wheel balancing machine. The wheels, despite being balanced according to the machine, have become slightly warped which is causing an apparent wobble. This is them amplified the faster the car goes.

Lexus Cardiff does not have a Dynamic Wheel Balancing service (where they balance the wheels when still onthe car so as to replicate the pressure and weight of the car on the road to further balance the wheel) - from what I understand (though there are also machines that have a 'Road Force' addition to a standard wheel balancing machine that replicates this too.

So they have advised trying this before considering changing tyres or rims.

royoftherovers · March 19, 2021

4 hours ago, paulrnx said:

Based on my past experiences of similar with both an A4 and a Jaguar XF, my money is on tyres that have worn slightly out of round at a point in their life. In both of my cases, replacing tyres fixed it. If you’re feeling it through seat of the pants I’d say it’s the rears. If you’re feeling it through the steering I’d say it’s the fronts. You could try swapping rears and fronts around to see if the symptoms move. A decent dealership or a professional tyre outfit should be able to run some tests to see if one or more of the tyres have worn out of round. Balancing an out of round tyre makes very little difference because the tyre circumference is no longer completely circular. Hope this helps a bit.

"out of round" = flat spot ?

Spacewagon52 · March 19, 2021

That is interesting as I have a vibration around 80mph. Only achieved that speed once (on a test track of course!) since I got the car. Not through the steering but through the seat. My tyres are 5 years old, so possibly that could be the issue also. The four figure age code on the tyres give it 2016. There is grazing on the rear tyre walls so I will change them. The car seems to have done approximately 15,000 miles on these tyres.

paulrnx · March 19, 2021

1 hour ago, royoftherovers said:

"out of round" = flat spot ?

Not quite. A flat spot would be if a tyre had been dragged across the road in a locked position causing a flat spot of worn tread or at least tread that wasn’t as deep as the surrounding area. My understanding when I looked into it more was that it was possible for some tyres to wear in an uneven manner around the circumference. Probably gives the same effect though.

royoftherovers · March 19, 2021

ok,thanks Paul.

paulrnx · March 19, 2021

3 hours ago, Stuart Aspey said:

@paulrnx

@Brechin Slate

Thank you both for your comments and suggestions. The mechanic brought me to the wheel balancing machine. The wheels, despite being balanced according to the machine, have become slightly warped which is causing an apparent wobble. This is them amplified the faster the car goes.

Lexus Cardiff does not have a Dynamic Wheel Balancing service (where they balance the wheels when still onthe car so as to replicate the pressure and weight of the car on the road to further balance the wheel) - from what I understand (though there are also machines that have a 'Road Force' addition to a standard wheel balancing machine that replicates this too.

So they have advised trying this before considering changing tyres or rims.

Warped wheels can also be fixed. It’s a simple test by a wheel repairer that has the right kit. I’ve had a warped wheel fixed by Reinventing the Wheel at Tewkesbury. They measured it with probably something like a dial test indicator to check it was warped. They then used one of their wheel presses to press it back into shape. I think they use a bit of heat to soften the alloy first. Never had any issues after and it did cure a slight wheel wobble that couldn’t be cured by balancing. Car was a 5 litre V8 Jaguar XF. Alloy wheels are quite soft anyway and can go out of shape what with the state of our roads. I was shocked to find out recently that a tyre being compressed against the side of a pot hole at speed can provide enough force (from the compressed air at the point of impact) to buckle a wheel. It doesn’t have to be the wheel itself hitting the pot hole that causes a buckle.

paulrnx · March 19, 2021

1 hour ago, Spacewagon52 said:

That is interesting as I have a vibration around 80mph. Only achieved that speed once (on a test track of course!) since I got the car. Not through the steering but through the seat. My tyres are 5 years old, so possibly that could be the issue also. The four figure age code on the tyres give it 2016. There is grazing on the rear tyre walls so I will change them. The car seems to have done approximately 15,000 miles on these tyres.

Could well be the tyres. If not, potentially a slight buckle/warp in an alloy wheel.

Stuart Aspey · March 19, 2021

Yes, it appears that a combination of cheaper (higher plastic content to rubber) tyre and a car not being used regularly can cause a tyre to become 'ovaled' a little bit like a flat spot.

There could be some of this with mine, but when on the wheel balancer, you could see that there was also a warping of the rim itself. So, even though the machine said everything was okay, you could see a movement of the wheel that would be amplified when on the car.

An Alloy wheel warped fixing service is very good to know about. I will try the dynamic wheel balancing first and when I'm ready to change the tyres, I might see if there is someone local that does this.

Stuart Aspey · March 19, 2021

4 hours ago, paulrnx said:

. I was shocked to find out recently that a tyre being compressed against the side of a pot hole at speed can provide enough force (from the compressed air at the point of impact) to buckle a wheel. It doesn’t have to be the wheel itself hitting the pot hole that causes a buckle.

Yes, I imagine that this is much more common on many more cars and drivers tolerate it.

paulrnx · March 20, 2021

15 hours ago, Stuart Aspey said:

Yes, I imagine that this is much more common on many more cars and drivers tolerate it.

It was one of the reasons that LED to me swapping my IS for an NX last July. The roads where I live can be dreadful in places and I just ended up driving around watching out for potholes. I buckled an alloy dropping into a pot hole that was covered with water. There was a bit of water right across the road and it was impossible to see it. There are way too many pot holes on our motorways too.