[aranciataoz]

Hi everyone,

I think this is my first post in like 10 years, and the first for my wife's GD i30 Tourer CRDi (auto, 2013). It's our family workhorse (two toddlers).

Firstly - technical background on our car - bought from dealer at 24k km in 2014, 65,000kms now, never had an issue, serviced by book. Has generally been a great perfect-sized car in the suburbs as well as out on the open road (we drive from Sydney to Coffs every year).

Lately, I've noticed a noticeable increase in road noise in the car, particularly at 60km/h - a humming noise, not exactly a "whoop whoop" type of noise associated with scalloped tyres (which I experienced many years ago), but a distinct hum loud enough to annoy me. As the speed increases the noise somewhat dissipates, but it's still there (maybe it's in my head at this stage).

I've discounted the engine as it seems to run smooth and with windows wound down the engine is no louder (diesel clatter) than it normally is.

My trusted tyre supplier and fitter of whom I've used for a decade, didn't find the tyres cupped/scalloped last week as I got him to do a wheel alignment and rotate the tyres (Pirelli Cinturato P1 - rear now front 60% life remaining, front now rear 40% life remaining). He confirmed the i30's dampers on both ends seem fine (simple bounce test) so it probably wouldn't cause tyre cupping/scalloping issues. So I've kinda discounted this as one cause of noise but still not convinced.

It could also be the bearings, but might need someone more experienced than me to work this out.

The most recent work on the car was the 60k km service 2 months ago, then 3 weeks ago I got the brakes done - pads replaced and rotors machine rear, pads replaced and rotors replaced front. Not sure either of this can cause the noise issue.

Anyway has anyone with a GD diesel experienced this, or is the diesel generally just like that ie. perhaps at the 60km/h mark the engine's usual gearing (4th) on a flat road (cruising but not accelerating), harmonically vibrates this hum? I've tried to gear change down at 60km/h to say 3rd and I can hear the hum reduce, but obviously the engine gets louder which is no help for diagnosis.

It's a puzzling issue. BTW yes our car is still covered by the OEM warranty but I don't want to book the car in for Hyundai lip service and me wasting valuable time. Any feedback from you all will be much more valuable early on.

Any advice appreciated!
Thanks


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[Asterix]

Since the tires have been ruled out and it didn't change the noise when they were rotated, I believe we can rule them out.

I'm on the bearings. If a front wheel bearing you should be able to change the noise when making a slight steering adjustment, meaning do the 60 km/h and then turn a little left. This will put the weight of the car on the right side bearing and if this increases the noise it's most likely your right front wheel bearing. Repeat with right turn for opposite side.

If this doesn't change the noise it's most likely a rear wheel bearing. I would take the car to the dealer as your still under warranty

[eye30]

Is the noise there on all road surfaces or is it only on certain surfaces?

[Surferdude]

I agree with Asterix re the bearings.
Have you tried slipping the box into neutral? If the noise goes away that would suggest some issue in the transmission.

[nzenigma]

I agree with Asterix re the bearings.
Have you tried slipping the box into neutral? If the noise goes away that would suggest some issue in the transmission.

Same here. Slight change of direction should indicate a bad bearing or CV joint. But do try neutral at 60km/h.

Interesting that you don't seem to be sure about the source; be it from front or rear and you also mention harmonic vibration. Interesting. 
In a past misadventure I spent a lot of time curing this sort of noise in new equipment. An unresolved discussion here about a year ago has caused me to become suspicious of the FD exhaust system. I suspect that it can be induced to vibrate and therefore produce a loud noise.

[Dazzler]

  and I must say, what an excellent post! So much detail, certainly makes our job easier to help you.

Can't really add any further suggestions to those already made, which were along the same lines as I was thinking.

Must say I am surprised that you needed new front brake rotors and the rears machined at that age and mileage! 

[aranciataoz]

Hey guys - thanks so much for all your detailed replies! Sorry I didn’t realise you had responded - I need to change my account email notification settings!

I’ll test the bearings as I drive home today and see what I find.

Will write more later ... so good to be back! :-)


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[aranciataoz]

Hi guys,

I managed to do a bit of road testing this morning while my toddler son was fast asleep in the car (it was too hot to sit by the roadside!).

Basically I first tried what Asterix suggested - the slight swerve to load the bearings up - apart from a bit of extra tyre scrub noise, no appreciable increase in the droan (noise) at around 60km/h. I must say bearing noises tend to be a lot louder so I'll rule this one out.

These are other things I noticed as the route I took was thankfully undulating, allowing me to test uphill/downhill too:

- there is no difference in droan levels when tranny is flicked to neutral, or when I'm jabbing the accelerator around 60km/h, so the engine revs up and down between 1400-2200 rpm (tranny's lock up converter clearly not engaged at this speed, allowing the engine to slip). So I can rule out the tranny and engine.

- the droan is loudest when the car freewheel slows from 60-50km/h DOWNHILL, and there is a discernable slow down in the frequency of the droan during the slow down .... there not much droan when the car is going uphill at 60km/h, possibly because the engine at around 2000rpm is drowning out the droan. But the droan on balance much louder when slowing down than gently accelerating around 55-60km/h.

That last characteristic almost convinces me the tyres are cupped/scalloped. I will have my mechanic sit in the car for tests next week, but most of all get him to run his hands over the tyre surface when the car's hoisted - I recall confirming this problem this way about 15years ago with another of my cars (tyres were those awful Bob Jane All-rounders ie. "Out-Of-Rounders" as the industry apparently called them).

And I would suggest the fact that the droan isn't noticeable at under 40km/h  makes sense in the case of cupped tyre, since the wheel isn't rotating fast enough for the cupped/bulge in the tyre to generate a frequency of noise against the road.

Likewise, the fact the droan almost morphs into a constant (but not as loud) hum of higher frequency from 70km/h also makes sense.

Anyway I guess until we hoist the car up we won't know - I'll confirm and even take some photos for you guys if it helps and if that's indeed the root cause!

BTW nzenigma, the droan was more noticeable in the back before I got the tyres rotated, but they're a bit more noticeable in the front now - another reason for the cupping theory, as the tyres were running for 25k km at the back (but the dampers are not worn), where the lighter end of the car often exacerbates cupping.

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[aranciataoz]

Dazzler re the brakes ... yeah I was kinda surprised the rotors needed to be done but then again most of our driving for the past 40k kms has been city based, plus being a diesel I'm expecting the brakes to work a bit more.

What I deplored about the brakes in our case was because the car is Czech made, the original brake pads were the soft kind - great feel and stopping power, but horrendous amount of brake dust caking the entire wheel, sometimes just 1 week after a car wash! My mechanic claimed he could machine the rear but not the front rotors as they were getting too thin - what I didn't understand was he said the soft pads wearing down quicker (than a normal metallic pad) may have worn the rotors down even quicker - strange because I always thought a soft pad would mean the rotors would last longer. Anyway ... they're all done now and with the new metallic Bendix pads now my wife correctly observed the brake feel is not as good and a bit more pedal effort is required especially when just starting journey.


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[aranciataoz]

Dazzler I noticed u have an i30 Tourer too but a petrol one - how do u find that? I love the torque of our 1.6 diesel, even if it's a bit gruff - I would expect the petrol would be pretty quiet?


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[Surferdude]

If it's the tyres, you need to check your rear alignment.

Feathering can be felt by the hands.
Scalloping or cupping is the longer term result of feathering.

However, also look for this. With the car in the air, measure (or in serious enough cases, eyeballing will do) the tread depth on the shoulders as you rotate the wheel.
You may find there is a gradual progression in the shoulder tread depth from almost normal to much less, then gradually back up to the high point.
In other words, an obvious high and low point in the tread on one shoulder. Could be inside or outside depending on the alignment setting.
Cupping or scalloping several times around the tyre would suggest a loose or badly adjusted wheel bearing.

Neither of these situations are the fault of the tyre. Both are mechanically caused.
The first condition above is often misdiagnosed as tread or belt separation. This is less likely these days but if that's what it is, the same tyre rotation inspection will show it up. There will be a difference in the tread depth but the outer circumference of the tyre at the shoulder will be still round, not showing a clear dip. 
In extreme tread separation cases, there'll be a clear bulge in the tyre.

That's all a bit confusing but I'm using a tablet and it's a pain typing.
Hopefully it makes sense.

[tw2005]

On both my FD hatch and CW which has independent rear as does the GD Tourer I believe.

I've had noise issues in rear left. The hatch got so bad I was convinced it was the hub. Changed that , no change. In hind sight I should have swapped the tyres but it was loud. Noise moved with it plus on closer inspection the inner edge of the  tyre was like a 50 cent piece. New KYBs all round and new tyres that fixed that.

Fast forward to the CW. had new tyres fitted to front and old to the rear. No issues. After a few months I started to notice a bit of tyre noise and a thud thud thud at very low speeds.  Replaced the tyres but then also noticed noise went but handling was weird, the left rear felt like the shock was getting the jitters around corners with and disturbance.

I still had the old rears and  close inspection of the left rear again starting to get squared off on the inner edge due to defective shocks.

They  felt fine most of the time. Anyway they have done about 68000k.  Out they went and another set of KYBs in the rear.

Feels a lot more precise but I still need to do more driving but definitely the hatch is real stable.

Not sure how accurate a bump test is, I'm thinking both of mine would have passed that too but I wonder if Pedders still has that shock test they run with a graph if that would expose anything.

Reading everything you said I'm thinking tyre noise but there could be an underlying issue like in my case shocks which have caused irregular wear.

[aranciataoz]

If it's the tyres, you need to check your rear alignment.......

Surferdude many thanks - this is Gold. Will have a go at your advice and get back to you.


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[aranciataoz]

tw2005 thanks - yes I'll confirm if the tyres are indeed abnormally worn and go from there. I'm well aware worn shocks can cause irregular tyre wear, but I sure hope it isn't the shocks ...


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[Surferdude]

I'd hope it's not shocks at 65 k.
But a failed one is always possible.
To simplify my above notes, several scalloping around the tyre would most likely be bearing or shock. The full circumference high to low wear would be alignment. Think of the tyre trying to be pulled off the rim but once every revolution it pretty much pulls itself back into line. This develops a pattern wearing in one spot more than the rest.

[aranciataoz]

I'd hope it's not shocks at 65 k.
But a failed one is always possible.
To simplify my above notes, several scalloping around the tyre would most likely be bearing or shock. The full circumference high to low wear would be alignment. Think of the tyre trying to be pulled off the rim but once every revolution it pretty much pulls itself back into line. This develops a pattern wearing in one spot more than the rest.

Thanks - this summary explains it well. I'll look for these patterns when car hoisted.


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[The Gonz]

These noises can be very deceptive. I've posted before that I was convinced my rear bearings were gone until I updated my OEM tyres to the mighty Chinese Diamondbacks. They may be all sorts of cheap but importantly they were ROUND!

Good job on your analysis so far.

[Dazzler]

Dazzler I noticed u have an i30 Tourer too but a petrol one - how do u find that? I love the torque of our 1.6 diesel, even if it's a bit gruff - I would expect the petrol would be pretty quiet?


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Funny you should ask, because it is the wife's car and I seldom drive it, but just drove it a 100 kilometres yesterday to the airport as flew to Western Australia to visit my dad.  Wife drove it home after of course.

It is a manual and I quite like it. Comfortable,  sure footed on the road. Has a nice gear change and is good on fuel. (Low to mid 6's)

Fairly quiet engine and on some surfaces (very coarse bitumen) it is probably quieter than my SR which has wider lower profile tyres.

I did miss the extra pep of my turbo though, even though the GDi motor is quite torquey on the highway.

Yes, the soft pads in the euro built models are a bit of a pain. Seems crazy that soft pads could wear the rotors more. Sounds dodgy to me!

[aranciataoz]

Thanks Dazzler. Awesome to hear about the GDi Tourer. I wish I had manual car of any sort but it'd be hell for my wife's dodgy ankles!

Hey re brakes am I allowed to link other forums? I just read the following where it's suggested Euro pads AND rotors are often designed to be soft:

http://forums.whirlpool.net.au/archive/2543355

Might make sense then what happened to me - I suspect both F & R pads had previously been replaced once and assuming the 2 pads per rotor theory then they were rightly due on the front. My mechanic tends to be straight down the line with me - at the last log book service for my Kizashi he deducted a fair whack from the fixed priced service as he suggested not to change the air filter as it wasn't that dirty, as well as the engine serpentine belt. So I doubt he would have replaced the rotors for a buck (that's what dealers do!!!).


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[Dazzler]

No problem using links from other forums. I often read whirlpool stuff. Good when you can find a mechanic like that. 

[eye30]

Is the noise there on all road surfaces or is it only on certain surfaces?

So seems this is a possibilty of the noise

[nzenigma]

Hi guys catching up on the weekend chatter, looks promising 

aranciataoz the movement of noise from back to front in conjunction with same wheel movement, convinces me that a tyre change is inevitable.
I often changed the original Hankook tyres because of cabin noise, this is an old complaint with the i30.

[aranciataoz]

Is the noise there on all road surfaces or is it only on certain surfaces?

So seems this is a possibilty of the noise

Forgot to add - same droan on all surfaces, but especially noticeable on smooth roads.

[aranciataoz]

Hi guys catching up on the weekend chatter, looks promising 

aranciataoz the movement of noise from back to front in conjunction with same wheel movement, convinces me that a tyre change is inevitable.
I often changed the original Hankook tyres because of cabin noise, this is an old complaint with the i30.

The current tyres giving me grief are actually Pirelli Cinturato P1's - by and large these have a great rep; had them on my old Sonata and as far as I know they're still going fine after 40k+kms (father in law has that car now).

My experience of Hankooks are actually quite the opp of most - when we bought the i30 tourer at 24k km's, the tyres on them were Ventus Prime 2's - hardly any tread left on them when approaching 40k, but to my surprise they were still quiet and quite grippy even in the wet - my biggest concern is often the front wheels skittling around a wet corner, but these were good. Same deal when I got my Kizashi 18 months ago - they came with the same Ventus Prime 2's, with not much tread left. But still gripped in the wet around corners, and quiet. I read up on them, and found tyre tests often putting these tyres up near the top. I bought them again for my Kiz 3 months ago, makes too much sense. I guess it may be a case of diff model tyres diff results, but the Prime 2's are brilliant.

[nzenigma]

I don't have a problem with wear on the Hankooks , they are just noisy especially, it seems, inside the petrol model that has less insulation.
Incidentally, keeping the fronts at 38 psi reduces the scrubbing.

[aranciataoz]

Hi everyone I’ve been wanting to give an update ...

Needing to prepare for our holidays I didn't get a chance to have my mechanic check out for cupping in our tyres.

But in my 500km trip up the Pacific Highway to our holiday spot, I learnt something new and was reacquainted with the great things about this car...

Firstly, I drove alone (wife kids flew up) but the car was packed to the rafters ... and I immediately noticed a huge reduction in the droaning noise around the 50-60km/h. The droan was still there, but much less noticeable. Makes me wonder if the noise is actually coming from the rear, and accentuated by the wagon cavity shape when it's not loaded with holiday luggage. Anyway I'm keen to see if the droan returns and at what level when I'm back in Sydney city driving. Above 80km/h the car cruises quietly.

On another note, I so enjoyed the long drive yesterday - I was reminded how well balanced this car is for young families - not too big on the outside for the city but big enough for long trips - OK there are probably quieter cruisers out there, but the great sounding stereo totally surprised me given they're the OEM speakers (I often makes it a point to immediately upgrade every OEM speaker but never found the need for this car). And I've taken for granted now how well the stereo connects seamlessly with my iPhone - I just streamed Sydney radio all the way (but surprisingly I had numerous dropouts on Telstra that rarely went to 4G when my other Optus phone was consistently 4G - anyway I'm digressing). This car's 528L boot is also incredible for such an externally compact car, and not many cars outside of Hyundai include a 12v socket in the boot - seems obvious but no! We rely on it so much to air pump the kids pool toys!

Anyway and with a towbar I've been reminded how blessed we are to have this car in this season of life ....


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[Surferdude]

In the hatch, even removing the parcel shelf increases cabin noise, so you're observation is on the money.
Incidentally it's the same in my Corollas.

[The Gonz]

It's a great carrier, isn't it? We recently bought our son a front-load washer after arguing the price down to minimum. Then came "Plus $50 delivery".

We said, "No thanks, we'll take it now". Can't do that in even most bigger cars.

[Dazzler]

@aranciataoz

Thank, we love to see posts like that. 

[aranciataoz]

Hi guys,

A final update ... after replacing the two most worn tyres over the weekend with two brand new tyres, that humming noise has now disappeared .... which confirms my mechanic's recent assessment that one or both of the tyres were out-of-round.

Looking back, I also think the out-of-round could have been caused by a previous puncture's patching - either way, it was definitely the tyres causing the hum. It's quite a relief now being able to drive and slow down to 55-60km/h without getting annoyed by the droan.

As an aside, in terms of the new tyres, I went against my longstanding commitment to never use cheap tyres, but could not ignore the outstanding consumer reviews for Winrun tyres, specifically the R330 ones. So I plonked for two of them during a 20% Fathers Day tyresales.com.au (I had a really bad experience with them back in their early days in 2014). Time will tell if my long term experience is as good as most reviewers', but early days are the tyres don't feel that different to the old Hankook Ventus Prime 2 (my favourite tyre) or the Pirelli Cinturato P1's.

Winrun and Hisense (in the AV world) remind me of Hyundai 15-20 years ago - solid good quality way beyond the asking price.

Anyway thanks guys for all your input into this droning noise issue - glad that for me it turned out to be the tyres.