VIBRATION UNDER ACCELLERATION AT HIGHER SPEEDS

[kevin]

Hey to all, recently noticed I am getting a disturbing vibration that is happening from 70+ under acceleration. I only have 15,800 on the car and it stays babied and in the drive way most of the time. This is crazy because it's got me really concerned on what it could be at the worst. Car is upgraded with PRO-Tuner and full Eibach Kit.

Anyone else have any issues like this? I am like, No way has a rear half shaft been bent at this point, but this is what I am speculating by the feel. I am a car guy and have lots of experience with cars, just seeing if anyone else has had a similar issue on here. Car is 2018 GT-2 RWD... BABIED!!!!!!!

 

[GTA Jay]

I would check the torque on your lug nuts first and see if one or more is loose. I once had this happen on my wife’s vehicle and the vibration was only noticeable above 125 km/h.

Secondly I would check the balance of each wheel. You may have one or more out of balance.

 

[kevin]

Yea, all those listed items above will be checked soon. Grateful for all input.

 

[MerlintheMad]

Then there's the more scary possibility that bolts are coming loose. We have the Utah guy (local) whose transmission "blew up"; no thread sealant on the bolts and they came loose. And two members have had one or more (up to half) of the bolts around their differential sheer off!? Producing vibration (ya think?). Admittedly, the "knocking in the back" was more prominent at low speed. But a beginning stage could manifest first at a higher, accelerating speed, long before the bolts sheer off.

 

[kevin]

Yea, that is what is scaring me. I will keep all posted. I love the car!!!
Gonna take it for a drive tonight and see if I can reproduce it with more details

 

[kevin]

Anyone on here had knowledge of drivetrain Tq. Bolt specs? Gonna get under the car this week and make sure drive shaft bolts and diff case are all tight.

 

[CKeeler]

Have the wheels balanced. I’ve noticed that mine goes out of balance every few months.

 

[cncBilly]

Anyone on here had knowledge of drivetrain Tq. Bolt specs? Gonna get under the car this week and make sure drive shaft bolts and diff case are all tight.

Great question. And you might want to think about doing that before you go out to try reproduce the problem. If that tranny drops at high speed you could end up being on a ride you don't necessarily want to be on. Or worse

 

[Dick Dastardly]

Won’t be wheel balance at 70mph +, you would get that at 30 or 40 mph.
Sounds like possibly half shaft bearings have gone, had that happen on a tuned Alfa Romeo which could not take the extra torque. Is pro-tuner a power chip?

 

[NismoDPB]

Is the pro tuner a piggy back ECU tune?

 

[cncBilly]

Is the pro tuner a piggy back ECU tune?

The same as hundreds run with no problem!

 

[NismoDPB]

The same as hunders run with no problem!

I'm sure it doesn't, if the plugs were gapped or changed

 

[kevin]

I don’t think so guys. Wheel balance and tire issues can cause lots of problems per any speed. Depending on how much the weights are off. I am getting tires balanced Sat. And a master Lexus tech is going over the drivetrain bolts. The car is brand new And it’s babied!! It has 15k on it and it’s been gently accelerated on! I will keep all posted on what’s going on. So Times the Internet can be misleading!! I am an experienced auto tech prior to being in my current career. All I can say is, I will update this post as soon as I know something. Car is new and it has to correctly dealt with on KIA’s dime

 

[NismoDPB]

Is the vibration associated with loss of power?

 

[CKeeler]

I don’t think so guys. Wheel balance and tire issues can cause lots of problems per any speed. Depending on how much the weights are off. I am getting tires balanced Sat. And a master Lexus tech is going over the drivetrain bolts. The car is brand new And it’s babied!! It has 15k on it and it’s been gently accelerated on! I will keep all posted on what’s going on. So Times the Internet can be misleading!! I am an experienced auto tech prior to being in my current career. All I can say is, I will update this post as soon as I know something. Car is new and it has to correctly dealt with on KIA’s dime

The last time I had vibration problems at highway speed I had the wheels balanced and the tech said they were well out. Smoothness restores. But I have a feeling these Michelin tires don’t wear evenly. I have to take mine in again to check the balance

 

[5tinger]

I was about to make the same thread. I have brand new DEC 18' build Stinger with only 800 miles.

There is vibration noise at speeds above 80kph / 50mph
Feels more intense when letting off gas after having reached above speeds.

Nothing in car physically vibrates - however the noise is very similar to a bad wheel bearing except it's a little higher pitched noise opposed to typical wheel bearing noise.
Also I cannot tell if it's emanating from front or rear.

I don't want to take car to dealer because I think they'll cause more damage

Any suggestions

 

[kevin]

It’s weird guys what is going on... it sometimes feels like a bad tire with a flat spot.... that smooths out with time and mileage put on vehicle, and sometimes it feels like an out of balance tire. I can say this, the car generates a very very very mild vibration from around 50 mph and up. It can be felt very slight in the steering wheel and sometimes in the passenger front seat. IE: Grocery bag at cruise 60 mph shaking the plastic bag ever so slight/

and sometimes it’s like it smooths itself out some what.... the car does have a pro Tuner on it, and it’s baby kept to say the least!! I am very gentle on it while accelerating!!! I usually don’t even WOT until it has shifted into 2 or 3rd gear because it’s lights up the Back tires slightly. The car has bald 2 consecutive strips of tread in the center of the tires and the rest of the tire looks new, or gently used. And air pressure mongers on here.... I do run proper air pressure! It’s just the nature of the extra power lighting up rear tires unfortunately. Also, I probably failed to mention. The car sits in my driveway for 5 days at a time before it is usually driven. All I can say is, as soon as I have a definitive resolution... I really don’t know what the deal is.... to many scenarios that it could be!
Also, I can Accelerate from a dead stop and WOT And the vibration doesn’t come on until around 70mph plus

 

[NismoDPB]

I was about to make the same thread. I have brand new DEC 18' build Stinger with only 800 miles.

There is vibration noise at speeds above 80kph / 50mph
Feels more intense when letting off gas after having reached above speeds.

Nothing in car physically vibrates - however the noise is very similar to a bad wheel bearing except it's a little higher pitched noise opposed to typical wheel bearing noise.
Also I cannot tell if it's emanating from front or rear.

I don't want to take car to dealer because I think they'll cause more damage

Any suggestions

AWD or RWD?

If it sounds like diff whine there is a recall (or service bulletin) on changing the diff oil.

 

[5tinger]

AWD or RWD?

If it sounds like diff whine there is a recall (or service bulletin) on changing the diff oil.

RWD. It's not a diff whine. This is more of a high frequency fluttering vibration at higher speed.

 

[kevin]

I have no noise guys! Intensity increases with speed, after 70+. Could be a separated belt ever so slight, off balance ever so slight .. etc. I will keep all posted! I promise guys, and gals