I'm desperate for help/ suggestions.

As per my 'Still vibrating' thread in Drivetrain, My car (MY99) is vibrating badly at all speeds. The suspension has been checked by main dealer and is OK. The car now has brand new Toyo's front and back, the wheels are balanced and the geommetry is spot on.

The vibration/ wobble feels exactly as an unbalanced wheel may do and is horrendous at motorway speeds. The steering wheel can be seen to vibrate back and forth. I also feel it through the accelerator pedal.
Under light throttle (off boost) the car can feel as though it is pulsing. Under WOT the car occasionally 'hiccups' before picking up and accelerating fine. On tickover the car intermittently jolts with a corresponding very slight drop in rpm.
Coming to a junction - as the clutch is depressed the revs either fall below 800rpm and then rise to settle at 800rpm or drop to 1000rpm (with much increased judder) before gradually settling to 800 rpm.
The wobble when driving I am coming to believe is as though I am feeling the engine moving from side to side as each piston fires!?

All sensors check out fine on Delta dash and I've eliminated wheels, tyres, alignment and suspension as the cause so what the f*&k is going on? The scoob experience is going very sour and I'm almost afraid to drive it with my kids in, things are that bad.

Please, please help.

Blobster

 

Blobster

I lost my STi5 engine to a duff MAF sensor. The first sign was a dicky tickover. Get the output voltage checked.

With regards to the vibes, I drove a mate up some of the farm tracks at brisk speed in my old 98. It had those OZ Super Legeras on and I bent 3 wheels. I got them balanced up and the vibration was still there. The nuggets at the tyre place hadn't checked that they were round. They weren't. They did still balance up ok though. Check yours are round my friend.

Dave

 

do WRX's have engine mounts, have they any history of breaking?

 

Give your engine and gearbox mounts a thorough check, I suppose at the clutching-at-straws stage you might check that the propshaft hasn't gone out of balance.

 

You say you have illiminated the wheels, have you swapped front to back or even try a different set if possible?

 

Wheels were changed front/back. Now new tyres.
This problem came on suddenly. The vibration and strange engine behaviour simultaneously.
Have no recollection of kerbing, hitting pothole or anything similarly harsh which might have buckled the wheels.
How do I check propshaft?

If I don't get this sorted soon I feel a Basil Fawlty coming on.

You know, tree branch, damn good thrashing, etc.

Blobster

PS. Still convinced it's engine related.

 

This might be worth a try!
Get a nice big hill on a quiet road and free wheel down it with the engine off and out of gear ,remember to keep the steering lock off and remember there will be no servo assistance on the brakes,if your still getting the shudder then its not engine related.(although i think the propshaft will still turn).

Also worth driving the car with all wheels off the ground to check for visible vibration on any of the drive shafts

[Edited by Trucker Ted - 1/25/2004 12:31:17 AM]

 

Once had an Evo 6 do this,really strange,was caused by faulty casting process on the alloy wheels,caused a harmonic imbalance and the car started to judder,as time went on it got worse and worse,actually felt at some stages that a disc had buckled and was shakin the hub about,but of course,didnt only do it under braking but this did seem to amplify the fault..just put a totally different set of wheels on..it will eliminate any probs with them at the very least..
Ta,
Gary

 

have you tried the wheel bearings dude ? i had the same judder in one of my old cars (not the scooby) ! worth a try ! and also had a problem with the tick over dropping on an mr2 ! it turned out to be the lambda sensor ! good luck matey

 

We had a MY00 with similar probs, more like a hesitation/shudder right through the car on motorway when accelerating from 2,000 revs. Turned out to be a multi plug on a injector not quite clicked in place properly.

Hope this is of help.
Gavin

 

Wheel bearings and other items being checked today.

I should point out this problem has come on only in the last month or so. After a year of relatively trouble free driving. Lamda sensor replaced six months ago.
There is no judder under breaking.

Thanks again. Keep suggestions coming.

Blobster

 

Billericay Davy, you were spot on mate.
After only five visits to dealers and two different tyre shops the vibration problem has been shown to be 2 buckled wheels.

Now where to get 2 RB5 alloys and a)can I afford them? and b)could I persuade the warranty co. to cough up?

Blobster