Resonance at 3800 RPM

Maya · **December 06, 2011, 19:18:56**

Hi Everyone!

We recently bought an i30 1.4 blue, petrol (manual transmission). From the day one it has a weird resonance: at 3800 RPM it becomes slightly louder and one can feel a vibration in the front part of the car (in the floor and in the pedals). Anything above or under 3800 RPM is fine, but this in the 5th gear unfortunately corresponds to a comfortable highway speed of 120 km/h.
I took it to three different service points and always got the same answer: " Yes, it vibrates, but technically nothing is wrong with your car".
Today I got the answer from the last one that made me even more angry: "This is the same in all i30 cars with 1.4 engine".
Is this true? Did anyone of you notice a similar resonance?
Thank you!

Dazzler · **Reply #1: December 06, 2011, 19:38:29**

Hi Maya ..

Welcome to the club. That is annoying

I can't help you directly with that as we don't get the 1.4ltr Petrol in Australia but I will bring it to the attention of Babis from Greece who has one.. I think quite a few other Euro members do too so hopefully they see this thread.

P.S. Please be patient with replys as some are only on here ocassionally.

accim · **Reply #2: December 06, 2011, 19:44:36**

Hm, there shouldn't be any vibrations. It's probably something with the tires, I would say or maybe the wheels geometry. It's true the car is loud above 120 km/h, but as I've said, don't think vibrations are okay.

As Dazz said, there are few members with 1.4 petrol engines on this forum, you just need to be a bit patient to get reply from them.

Phil №❶ · **Reply #3: December 06, 2011, 20:25:17**

I don't think that is acceptable. At those revs, the engine should be ticking along quite nicely. If you're an experienced driver AND you can find a long safe road, try taking the car just up to the vibration speed & record the speed, then drive past the vibration speed and put the car in neutral. Let the engine revs drop to idle & as the speed bleeds off, see if there is any vibration. If not, then it's not the tyres & associated components. If there is, then it's not the engine. That's all I can suggest.

Please only perform this test if you are experienced and road conditions are safe, as it is dangerous to put the car in this configuration.

Dazzler · **Reply #4: December 06, 2011, 20:30:47**

Good suggestion Phil

Maya · **Reply #5: December 06, 2011, 21:53:57**

Wow, thanks for your prompt responses!
Actually, I already performed the test with shifting to neutral. The car vibrates only for as long as I am in the gear (with the appropriate number of RPM), in neutral everything is fine. I assume it has to do with the engine, since it always happens at the same number of RPM (with summer tires and winter tyres alike), but all the mechanics who took a look are trying to persuade me that this is all perfectly fine--that is really annoying.

Surferdude · **Reply #6: December 06, 2011, 23:12:33**

It's strange it only happens in fifth gear.
So not an engine issue methinks. Nor tyres if it happens with both.
But maybe the transmission. Or possibly a drive shaft.
I'd be suggesting to them that the international i30 Owners Forum has reported no other members with this problem in a 1.4 model.

Phil №❶ · **Reply #7: December 07, 2011, 00:37:46**

Is 3800 revs in any other gear ok. That would rule out the engine and leave only the transmission. Is it a recent problem, I presume it wasn't there when you test drove the vehicle. If it's not there in any other gear except 5th then I would suspect the 5th gear power train arrangement. But why @ 30k.

Surferdude · **Reply #8: December 07, 2011, 00:59:30**

Just re-read the original post and may have misunderstood.. 84's query re the other gears is a good one. because you mentioned 5th gear specifically, I assumed

it was only that gear which was a problem.
If it's at those revs, regardless of the gear, that sounds pretty serious inside the engine.

diablo · **Reply #9: December 07, 2011, 03:53:05**

I have a 1.4 petrol and although mainly a town car have many times driven at around 75 mph (equivalent to 120 km/h) on the motorway.

Never noticed any vibration at all with mine.

I'd also expect it to vibrate at 3800 in any gear if it was the engine. Maybe try it at 3800 in fourth up a slight hill to simulate the higher workload at the faster speed - if you know what I mean.

Alasama · **Reply #10: December 07, 2011, 03:59:34**

For this case, personally I think 3800rpm is the resonant frequency of something related (directly or indirectly) to the engine. Maybe it's not the engine problem, but really hard to find out what is causing this vibration. (this frequency did not apply to every car)
I also feel unusual vibration in front of me "only" during 1800~2000rpm on my 1.6CRDI. It has been 1 and a half year, I did not find out the root cause yet. But it's nothing to do with the engine.
Recently my bike has vibration at 8000rpm (at any gear), too, which I never heard it before.

Hopefully your case is just like that simple.

Maya · **Reply #11: December 07, 2011, 07:27:50**

Sorry, I probably wasn't clear. It happens at 3800 RPM regardless of the gear (it is just that I drive the highway every day and it is especially annoying that it happens at the speed I drive most of the time). I am going to the handler today and will press for a contact with Hyundai. This is a new car and such things shouldn't happen.
I'll let you know how it goes.

Thanks for your responses, now I can tell them that "this vibration is normal" is not a correct answer.

MadCornY · **Reply #12: December 09, 2011, 16:50:26**

Maya, when this is happening, does your steering wheel vibrates too?

Maya · **Reply #13: December 15, 2011, 13:55:44**

Hi MadCornY,

Sorry for the delayed response, I haven't been around these days. The wheel does not vibrate.

In the meantime I managed to get an appointment with a Hyundai service specialist (not sure what distinguishes him from a "regular" Hyundai guy), so some time in January I might have an answer to the mystery (or not).

Phil №❶ · **Reply #14: December 16, 2011, 04:23:03**

It would be a good idea to drive another car of the same spec and close to your kms just to prove that your car is different. Can your helpful dealer arrange this. They may have one in stock.

MadCornY · **Reply #15: December 16, 2011, 16:08:00**

I asked as my i30 starts vibrating at 142 km/h up to 155 . I guess my problem could be simple for example, need for new tires or some balance/alignment issue.

Phil №❶ · **Reply #16: December 16, 2011, 22:31:52**

155 in a 1.4L,,,,,,,,,,, V1, V2, Rotate!

Asterix · **Reply #17: December 16, 2011, 22:53:37**

According to Hyundai.dk the topspeed is 187 km/h..!

So there should be much more power in that little 1.4 engine

Tophastighed (km) 187

Phil №❶ · **Reply #18: December 16, 2011, 22:55:46**

Er, that's about 100k past the most efficient driving speed, but, to each his own.

babis_xo · **Reply #19: December 25, 2011, 11:19:38**

Merry Christmas!
Actually noise is pretty annoying at exactly 3850 rpms (for me) and there is also a sliiiight vibration (not to the point of beeing annoying by itself) which I can't determine where it is from. And I'm too sensitive to the various noises and vibrations.

EDIT: It was really annoying when the car was brand new and engine components were stiff. Should be much better after 10.000 kms or more

abou · **Reply #20: December 30, 2011, 12:39:40**

Hi !
Also had a 1.4 petrol i30, and no external noise or vibrations at any rpm... just a vibration inside from the front mirror (fixation system because I can stop it by holding the mirror).
By the way, 1.4L petrol engine does go up to 190 km/h... without any vibration (I got Bridgestone Turenza tires) !
Hope you will solve your trouble.
Happy new year !

Dazzler · **Reply #21: December 30, 2011, 21:42:04**

Quote from: abou on December 30, 2011, 12:39:40

Hi !
Also had a 1.4 petrol i30, and no external noise or vibrations at any rpm... just a vibration inside from the front mirror (fixation system because I can stop it by holding the mirror).
By the way, 1.4L petrol engine does go up to 190 km/h... without any vibration (I got Bridgestone Turenza tires) !
Hope you will solve your trouble.
Happy new year !

babis_xo · **Reply #22: January 02, 2012, 12:47:59**

GPS showed 185 km/h (semi-full load, flat road, only 10.000 kms on the car). I'm sure it can do better than this now, though I'm not going to test it

Phil №❶ · **Reply #23: January 02, 2012, 20:53:20**

I'd say you already have.

babis_xo · **Reply #24: January 03, 2012, 13:00:40**

Typically, it has 1-2km/h more to give

vodnokoki · **Reply #25: November 03, 2012, 13:59:47**

I have this problem too, mine is 3 years old with 30.000km. I never drive my car on 120km/h, it's annoying sound vibration!!!!!! I always drive more or less from 120km/h.
I have friend that has a Mitsubishi Lancer 1.5 109HP, he has the same resonance.