Lazy

iTrader: (2)

Alrighty uhm.. I have an 03 is300 stick n when I am in 5th gear around 2k rpm n up my car starts to shake and it's very noticable + scary.. Anyone have a clue what it might be? Car drives fine when below that and in lower gears. It feels like it is in the driver front but it shakes everywhere.. If anyone knows anything about it let me know asap plz.

masagsxr

Maybe your knuckle bolts are loose.

O. L. T.

iTrader: (17)

You are actually just at a point where you are relaxing the driveline. Cruising at 5th gear near idle would be similar at a slower speed with little to no pressure on the driveline you'd notice the same thing most likely. It's things like the driveshaft damper or possibly an engine mount. Something rubber, something in the drive line, something that prefers to show itself when the driveline doesn't have torque applied. On the SC's it is the driveshaft coupler that does this, but I dunno if the IS has the same setup.

UNOHOO

iTrader: (3)

either that or you lost a weight on your wheels/one wheel is slightly under pressure/broke band in youre tires/loose lugs

have you checked all of that kind of stuff yet?

another troubleshooting step is figure out what speed it does this and then go that speed in 4th (if you can) and see if it does it

Lazy

iTrader: (2)

does it in 4th at the same seed and higher. I tighten all the lugs n changed to different sets of wheels. I will check th knuckle n other parts today. Thanks for the quick answers.

UNOHOO

iTrader: (3)

try going that speed and putting it neutral, that will tell you for sure if its the drive train or not, if it continues to do it with the car in neutral you KNOW its not the engine or tranny

Lazy

iTrader: (2)

In neutral it stops but around 800 rpm it starts again but really weak. It also shakes when I brake at a little higher speed. What do you guys mean by losing weight on my wheel? I changed the wheels to another set today and it still shakes. All lug nuts are tight n pressure on all tires are the same at around 35-40psi.

IS3_FTW

iTrader: (3)

Your wheels are balanced by weights. You might need to get your wheels re-balanced

LexusGSXR

i put my tire pressure at 34psi all around my 18's.. makes it wear even.

i dunno whats wrong with ur car..

UNOHOO

iTrader: (3)

i meant balancing weights but if it stops when in neutral then its definately not your tires/wheels/bearings or anything thats moving when you drop it in neutral

O. L. T.

iTrader: (17)

I just told him at the start of the thread it is load based. Go get your driveshaft inspected.

UNOHOO

iTrader: (3)

yea i just wanted to be clear as sometimes i know people can read things differently than you hear it in your head when writing it ya know? happens to me sometimes

Lexatlast

iTrader: (5)

do you think it may be tranny mounts?

O. L. T.

iTrader: (17)

Lawl, I'm just ribbing ya.

Lazy

iTrader: (2)

I have been busy to update or do anything to it so far.. Is it ok to drive on it? I am gonna check it out 2morrow since I will be free. Is there anything else I should be looking for?