Vibration still !!!!!!!!

[vs2DSIRE]

gday all again i still have my vibration threw my car and its getting very frustratin now . so i replaced ATS , COIL PACKS, LEADS , PLUGS , O2 SENSORS, TRANS MOUNT , EXHAUST MOUNTS ROCKER COVER GASKET . I have cleaned throttle body IAC TPS Plenum chamber. DFI board to remove corrison . the problem is it vibrates at idle in DRIVE and REVERSE only . but it drives very well when not idling . i raised the idle to about 900 rpm in neutral when hot and it helps but when its cold it sits about 800 rpm and the vibrations is there till it reachs normal operating temp witch is about 10 to 15 mins of driving , . i did have extractors put on and a high flow cat when i first got it but the vibration didnt accure tilll a couple months after it getting installed . i spoke to one mechanic about the exhaust being to stiff because the driverside extractor sitts lower than the passengers side one about an inch lower and it seems stiffer than the passenger one . so toke it the an exhaust specialist he seems to think its fine ????? no sure about that one . so i dont no where to aim next . i have had my HARMONIC balancer checked and its fine 2 mechanic seem to think my ENGINE mounts are fine. so my problem is that when my car is cold it vibrates pretty bad when in D but once warm it seems to brighten up a bit and seems less serve but still there . also when i go on long trips and have the car running up the highway for a couple of hours an i come to set of lights there is no vibrations feels smooth as ????? . any help would be muchly aprreciated as i have been trying to figure out the go for about a year now

[hako]

Not all engine mounts are the same - original factory units are silicone oil filled (hydraulic) designed to smooth out vibrations whilst aftermarket ones from Repco etc are just straight rubber. Not sure if this is your problem but something to think about.

[nathanVY]

I have exactly the same issue, replaced almost everything. Harmonic balancer is next on my list.. not sure what else i can do.

[sleepyjean]

could be, torque converter even check to see if all bolts are in it, flywheel bolts loose, just that when its revving higher the vibration goes thats what makes me think that may be where the problem is. like the fluid is locking up the problem with revs, more pressure in the converter

[somefool]

i wish they made the torque convertor inspection cover a little easier to access - 9 bolts/nuts 6 of them hidden under the cross member then having to drop the steering rack and still cant get it off . gah!

[vs2DSIRE]

i no that one off my engine mounts is a new one and the other is original . Is here possibilty that my eexhaust is to rigid and when cold he doesnt have enoung flex and causing it to b stiff when cold and once hot the pipes are less stiffer witch would make sense becuase the vibrations goes away when it is a operating temp ????? And nathanvs i have read your post and your issue sounds very much alike mine mate

[hako]

As it only has the vibration in D and R that means only when the engine is under 'strain' and trying to twist in relation to the body of the car.....also the revs usually drop by ~ 100rpm cold but only maybe 50rpm when hot (when vibration goes away).
That seems to point towards the exhaust....so maybe replace or modify the exhaust hangers and see if that makes any difference.

[nathanVY]

As it only has the vibration in D and R that means only when the engine is under 'strain' and trying to twist in relation to the body of the car.....also the revs usually drop by ~ 100rpm cold but only maybe 50rpm when hot (when vibration goes away).
That seems to point towards the exhaust....so maybe replace or modify the exhaust hangers and see if that makes any difference.

I've had this issue since I got the car, except the standard exhaust used to rattle (header flanges were ugly lookin' things) - now it's full custom and still does it only just!

I've noticed a slight vac leak from my IAC, so I'll try and re-seat that properly might need a bit of oil around the gasket to slip in properly.

[vs2DSIRE]

could a dodgy dfi cause this problem .

[nathanVY]

could a dodgy dfi cause this problem .

surely if that was the case you'd notice it when you loaded up the engine, accelerating etc.

[vs2DSIRE]

yer you would think but i think it controls the idle . If was buggered it might be givin a shit spark st idle . Also k noticed that at the back right rear the is a hose that hass snap off that comes from the tank around to the back of the tank ????

[hako]

Maybe also reset the idle to 100rpm higher and do this the proper way by the book so that the IAC can still control the idle. Maybe your tacho is over-reading.

Re tank hose...that's a possibility too as a vacuum line goes to the tank

[nathanVY]

Maybe also reset the idle to 100rpm higher and do this the proper way by the book so that the IAC can still control the idle. Maybe your tacho is over-reading.

Re tank hose...that's a possibility too as a vacuum line goes to the tank

Interested to know more about the vacuum hose...

[vs2DSIRE]

yer mine snap when i jacked the car up one day and i started the car up after woodd and it was fine so i didnt think much off it . But maybe it does have something to do with it . As for the idle iam unsure off how do raise the idle threew the iac doesnt it have to be set 28mm from the end and that is set right ?????

[hako]

There is also a "purge valve" that opens above idle and allows vacuum to be applied to the charcoal canister....if the purge valve is sticky it may be open at idle. You check this (I think) by schecking the vac line from manifold to purge valve at idle.

[hako]

yer mine snap when i jacked the car up one day and i started the car up after woodd and it was fine so i didnt think much off it . But maybe it does have something to do with it . As for the idle iam unsure off how do raise the idle threew the iac doesnt it have to be set 28mm from the end and that is set right ?????

28mm is correct. You need a Gregorys manual!!! PM me your email address and I'll scan the base idle page for you. Just turning the screw upsets other parameters!

[vs2DSIRE]

i fixed the vac line runnung to the tank no luck with that i also noticed that the idler atm moves abit up and down wen in drive it movesjust upand down and makes a ticking kinda knock sound ????

[vs2DSIRE]

??????????? ????????????

[98NVS]

change wheel bearings on front. had same problem

[vs2DSIRE]

well toke her to a different mechanic outta town just to see what they had to say and they said theres not a bad thing about my car everything looks good . they couldnt tell me what the vibratation was because dont no were to start , nothings wrong , i also gota exhaust specialised out to have a look they said everything looks really good no problem ??? ive got no idea now haha pretty funny now

[nathanVY]

Yep that's what everyone said here too

[SavVYute]

Check your exhaust system for a flexible connection similar to this.
They seem to wear out a bit over time and jiggle about a bit at idle causing a rattle.

[nathanVY]

yeah mine does not have anything like that, all custom. =\

[SavVYute]

If the vibration goes away or changes when your car warms up - and/or when the RPM increases it sounds to me like the problem is exhaust related.
Have you tried undoing the connections along the length of the exhaust pipe, shoving it all around a bit to reallign it and doing it all up again?

[nathanVY]

If the vibration goes away or changes when your car warms up - and/or when the RPM increases it sounds to me like the problem is exhaust related.
Have you tried undoing the connections along the length of the exhaust pipe, shoving it all around a bit to reallign it and doing it all up again?

Now i haven't tried that... my exhaust is pretty stiff. But the engine shakes around heaps, I'll sort out all the vac leaks first I reckon.