IS200 vibrations

[LavaIS]

Hi, I’m a new member on Team Lexus! Just joined you yesterday.

Reading thru some of your discussions made me more eager for a TTE SuperCharger than ever... But I’ve one problem with my car, some nasty vibrations when the car’s loaded (around 4 persons), and I push the pedal for an overtake. If those vibrations comes with a stock engine, I would expect it to get worse with more power. Lexus/Toyota in Norway already changed my gearbox (yeah, it’s a 1999 6MT...), my cardan joint and my driving shafts. But most of the vibes still exists.

Any suggestions on what causes the trouble?

Rgds,

LavaIS

[Edited on 22-3-2002 by LavaIS]

[brn7y]

This may be a stupid question, but have you done these 3 things?

1) Checked your tyre pressures.

2) Checked you wheels are balanced.

3) Checked your wheel alignment.

[brn7y]

Also have you checked the engine mounts for damage ao loosness.

[LavaIS]

Thanks for caring!

These vibrations have occured with 3 different sets of wintertyre, and 2 sets of summertyre. All were well balanced. Under normal driving condition, when I'm the only one in the car, the vibrations are hardly noticeable.

The wheel alignment are checed by Lexus once, and I've just ordered a new check.

The vibes been there from the car was new, and totally stock. Still here with lowering suspension (alignment was made after mounting of suspension kit).

Rgds,

LavaIS

[LavaIS]

Well, engine mounts are not checked, as far as I know...

[red6]

I get that horrible shaking stability problem now and again on the motorway when it feels like there's a force 10 wind coming sideways on. I think its always happened as I'm accelerating through the gears. That might be due to different rear tyre manufacturers to front (Lexus did that). Are your's the same make all round?

[LavaIS]

The tyres are of the same make, and dimension all around for all my wheelsets.

I have tried:

2 sets of 205/55-16 wintertyre (Michelin & Continental)

1 set of 215/45-17 wintertyre (Pirelli)

1 set of 215/45-17 summertyre (Dunlop)

1 set of 225/40-18 summertyre (Dunlop)

Pressure and balance should not be a problem. I've varied the pressure a little, just to see if that's make a differ. I can't say i felt any difference on the vibes. Handlig however, seems to be very affected by the pressure.

Just to be sure, I've sent a set of tyres to be rebalanced today.

I mentioned that I had my gearbox changed. The old one made an awful rumbling noise on the 6'th, from approximately 80km/h to 120km/h. The new one is still not perfect, but a lot better. This rumbling noise and vibration however, differ quite a lot from the vibes comming when I'm accelerating when the car is heavy.

Rgds,

LavaIS

[weltmeister]

What about your shock breakers ???

Did the car has accidents before ???

[LavaIS]

I'm not quite sure what you're meaning with "shock breakers".

If it's the shockabsorbers you're refering to, I've had 2 complete sets of original ones, and now a set of Koni Sport.

The vibrations been there since the car was new and undamaged. I had a little accident last year, but it did not make any diffence on the vibes.

Rgds,

LavaIS

[Monster-Mat]

hmmmmm,strange one this,ive pondered many a night,i would have said that if this was so since having the g-box done that the prop shaft could be out of balance....

however you say its been so since new.......very strange.....

i really am stumped on this one,i would have all the mountings checked,both engine and g-box as you said after the new box the vibrations were not as bad,also see about the prop shaft,it may be a faulty one before fitting,but since being moved and refitted its been put on in a differing possition(hard to explain unless you understand propshafts)

it could have faulty splines,flanges or UJ'S

[LavaIS]

I've now got my wheels balaced, made NO differ, as I expected...

I also had my car "checked" by Toyota/Lexus. When they rang me back and said the car was finished. I asked about the vibrations, and he said it was fixed. When I got my car back home, loaded it, and took a testdrive. What a differece - NOT!!! Drove back to Toyota the very next day and complained. The same guy that told me the car was "fixed", now tells me that they'd testdrived the car, and that the vibes are the same for all the IS's, so they didn't do anything with it, not even the alignement of the wheels as we agreed upon... Hmm, do I use too much madfaces in my treads....?

Anyway, I'll turn it in once again next week, for the alignement at least. I'll try to borrow a 02-IS to check later this week, to see if it's only me that's picky. Maybe I am, but the red line through all that involves Lexus is the word smooth....

Anyway, I have established that the vibes only comes when the car is heavy and low in the rear. Towing another car is not a problem, so it can't be the momentum on the engine that causes trouble.

My conclusion then, is that the engine and G-box mounts are OK. The cardan joint as well. Both the rear drive shafts are (supposedly) changed...., but somehow the angles on these must be involved, or the alignement on the rear wheels when loaded.

Well, we'll see next week, but my hopes are not too high:(

It is very sad that these irritation moments destroy the feeling of the splendid car that the IS is.