Vibration when accelerating?
Jul 11, 2011, 12:59 PM
#31
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There appears to be ample clearance on mine but its obviously moves quite a lot under load as the prop had a wear band through the paint and a clean area on the exhaust box. It was the side of the box so it wasnt an edge that might make more of a scraping noise.
I'm pretty certain its this as its almost gone now but I just looked under again and can see it must still be hitting as the wear band on the prop is clean still and a little wider as the contact are has moved slightly by attempting to move the pipe out of the way.
My only guess at why it happens is now its lower under full boost/load the new drive angles cause the car to squat more maybe and that makes either or both the prop / exhaust to move closer than they do with usual ride height/drive angles???
I'm pretty certain its this as its almost gone now but I just looked under again and can see it must still be hitting as the wear band on the prop is clean still and a little wider as the contact are has moved slightly by attempting to move the pipe out of the way.
My only guess at why it happens is now its lower under full boost/load the new drive angles cause the car to squat more maybe and that makes either or both the prop / exhaust to move closer than they do with usual ride height/drive angles???
Jul 19, 2011, 01:11 AM
#33
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I took the time to jack the car up and move the exhaust again. I got as much clearance as possible but upon testing the vibration is still there 
well gutted...
I'm thinking now that its a prop thing, my effect is more noticeable when the car is under compression (going up hill of when coming down then up) Is it possible the prop is getting pressure from either end now the car is lowered making it deflect (and hit the exhaust in my case) and vibrate???
Really p-ing me off now this
well gutted...I'm thinking now that its a prop thing, my effect is more noticeable when the car is under compression (going up hill of when coming down then up) Is it possible the prop is getting pressure from either end now the car is lowered making it deflect (and hit the exhaust in my case) and vibrate???
Really p-ing me off now this
Jul 19, 2011, 06:42 AM
#34
I believe it to be a CV problem as well...that is what you are referring to, right?
After putting my Swift Sports on (coming from Eibachs), I noticed that the vibration disappeared; well, when you have a few people in the car, it comes back. Makes sense as the car is lower. My guess is that same issue would arise with stock springs. Can anyone verify? I don't see why it wouldn't still be a problem when the car is fully loaded. I might have to slap mine back on and then take it to the stealership and see what they say. It's very strange that some people have this issue and some don't.
After putting my Swift Sports on (coming from Eibachs), I noticed that the vibration disappeared; well, when you have a few people in the car, it comes back. Makes sense as the car is lower. My guess is that same issue would arise with stock springs. Can anyone verify? I don't see why it wouldn't still be a problem when the car is fully loaded. I might have to slap mine back on and then take it to the stealership and see what they say. It's very strange that some people have this issue and some don't.
Aug 12, 2011, 10:43 PM
#35
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My car vibrates pretty much every morning once exceeding about 80 km/h. Temperatures drop from 20* C during the day to 5-10* in the morning. It feels like a wheel off balanced but once on the highway for about 5-10 minutes it goes away. Weird.
Oct 4, 2011, 07:27 AM
#36
Anybody in this thread resolve their issues? I've pretty much been living with it I guess. The only time I notice it is when I'm hard through a turn (loading the suspension very hard) or accelerating in a straight line with people in the back seat (again with the suspension loaded). In a straight line under boost with just me, there is no vibration, maybe very slight vibration in fourth. It feels like it's coming from the back as I feel it in my seat and not the steering wheel.
Oct 23, 2011, 12:22 PM
#37
This really sucks to have your car looking nice and lowered and for it to be vibrating like this. Last night I had 4 ppl in the car and noticed the vibration more pronounce going at high rpms. So it seems like it's definitely related to the ride height of the car.
For reference I'm lowered on BC coilovers, Harmon motive mbc, snapse bov, 18x9.75 +20 wheels, magnaflow exhaust.
Any fix for this other than raising the height???
For reference I'm lowered on BC coilovers, Harmon motive mbc, snapse bov, 18x9.75 +20 wheels, magnaflow exhaust.
Any fix for this other than raising the height???
Oct 26, 2011, 10:16 PM
#38
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my evo started makinng the vibration noise from 3800rpms to 5000 rpms during light trottle in any gear, only when i hit small bumps in the road. I know its not the tranny or cv shaft , because i can free rev it 4000rpms with the clutch pressed in, it will make a vibration noise hitting small bumps. It cant be the clutch ,because it doesnt make the noise when car not moving or not going over a bump.
It started to do it after a hard 3rd gear pull a few weeks ago.
It started to do it after a hard 3rd gear pull a few weeks ago.
Oct 27, 2011, 05:09 AM
#39
my evo started makinng the vibration noise from 3800rpms to 5000 rpms during light trottle in any gear, only when i hit small bumps in the road. I know its not the tranny or cv shaft , because i can free rev it 4000rpms with the clutch pressed in, it will make a vibration noise hitting small bumps. It cant be the clutch ,because it doesnt make the noise when car not moving or not going over a bump.
It started to do it after a hard 3rd gear pull a few weeks ago.
It started to do it after a hard 3rd gear pull a few weeks ago.
Jan 10, 2012, 08:11 PM
#41
Anybody in this thread resolve their issues? I've pretty much been living with it I guess. The only time I notice it is when I'm hard through a turn (loading the suspension very hard) or accelerating in a straight line with people in the back seat (again with the suspension loaded). In a straight line under boost with just me, there is no vibration, maybe very slight vibration in fourth. It feels like it's coming from the back as I feel it in my seat and not the steering wheel.
Can someone find a fix for this phantom issue? I refuse to raise my ride height.
Jan 12, 2012, 06:52 PM
#42
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UPDATE:
Ok so had the car up on a ramp and I had a look around. I have a Milltek turbo back decat exhaust fitted which has a resonator box before the rear box. For some reason now the car is lower the corner of this resonator box had been rubbing on the prop shaft under full load! On the ramp there was about 1/2inch clearance but obviously under full power they were touching. We adjusted the distance as much as possible giving about 3/4inch clearance with the car sat on the ramp. This has almost cured my problem but its still touching a little so I need to make an adjustment to the corner of the resonator box once I can get it back on a ramp (hammer time).
I dont know if I have another problem (engine mount or prop guide) thats allowing these to touch or why lowering the car suddenly caused the two to touch as they didnt before, good few thousand miles with the Milltek fitted b4 lowering...
Thought I'd post as I found my answer to this problem, it could be the same for you.
Ok so had the car up on a ramp and I had a look around. I have a Milltek turbo back decat exhaust fitted which has a resonator box before the rear box. For some reason now the car is lower the corner of this resonator box had been rubbing on the prop shaft under full load! On the ramp there was about 1/2inch clearance but obviously under full power they were touching. We adjusted the distance as much as possible giving about 3/4inch clearance with the car sat on the ramp. This has almost cured my problem but its still touching a little so I need to make an adjustment to the corner of the resonator box once I can get it back on a ramp (hammer time).
I dont know if I have another problem (engine mount or prop guide) thats allowing these to touch or why lowering the car suddenly caused the two to touch as they didnt before, good few thousand miles with the Milltek fitted b4 lowering...
Thought I'd post as I found my answer to this problem, it could be the same for you.
For others out there, besides clutch, a few simpler things (i.e. cheaper and fast to check):
1 - a tire will do this as it gets any type of belt protruding. Rear tires make the sensation stronger. Check out your wheels, just remove them and rotate them, feeling them with your hand as you roll it on the ground. With AWD, f could cause it but weight transfer would hide this on acceleration
2 - because we Evo guys tend to accelerate more often with a bit if "spirit", a poorly poured concrete road or asphalt that's got some washboarding in it that you cannot see can also give this symptom. Find your self a few known smooth and bumpy roads, try it out and see if that's causing the sensation.
Cheap advice, throw it away if you want.
Last edited by journeymansteve; Jan 12, 2012 at 06:54 PM.
Jan 13, 2012, 05:56 AM
#44
All good things to check, unfortunately, I've done all of this, exhaustively. Some things to note.... I've put my stock springs on, and the vibration is COMPLETELY gone. None whatsoever. BUT, with a car load of people, it comes right back. I'm absolutely 100% certain, that is' ride height related. With Eibachs, it was quite noticeable with just me in the car. Swift Sports, less noticeable but still just barely there, with stock springs, it's gone. Load up the back of the car with a couple fat asses, it's back. Mind you, these vibrations are only under WOT and most noticeable in the higher gears (3 and up typically). I've already made one trip to the dealer. They could not replicate the problem. Next trip I'm going to take a ride with a few techs loaded in the car to show them specifically what I'm talking about. I have a good feeling that it's the rear half shafts. The CV joints are at an angle that is allowing them to resonate or vibrate under torque. As I've said before, just google "vibration under acceleration". Lots of threads with lots of different makes and models. VW guys experience it, Mini's, Hondas, all kids of cars. The only thing that frustrates me is that it seems to be a hit or miss things on the Evo's.
I had a real gremlin with my exhaust clearance after first install. It would rub, but ONLY during a heavy downpour -- cats and dogs style. And it didn't vibrate or jerk, it SCREAMED and rang like a siren. It now sits what appears to be double the distance, maybe 1/2" now. The thing does move, and apparently heat differentials can cause something odd to move and change clearances.
For others out there, besides clutch, a few simpler things (i.e. cheaper and fast to check):
1 - a tire will do this as it gets any type of belt protruding. Rear tires make the sensation stronger. Check out your wheels, just remove them and rotate them, feeling them with your hand as you roll it on the ground. With AWD, f could cause it but weight transfer would hide this on acceleration
2 - because we Evo guys tend to accelerate more often with a bit if "spirit", a poorly poured concrete road or asphalt that's got some washboarding in it that you cannot see can also give this symptom. Find your self a few known smooth and bumpy roads, try it out and see if that's causing the sensation.
Cheap advice, throw it away if you want.
For others out there, besides clutch, a few simpler things (i.e. cheaper and fast to check):
1 - a tire will do this as it gets any type of belt protruding. Rear tires make the sensation stronger. Check out your wheels, just remove them and rotate them, feeling them with your hand as you roll it on the ground. With AWD, f could cause it but weight transfer would hide this on acceleration
2 - because we Evo guys tend to accelerate more often with a bit if "spirit", a poorly poured concrete road or asphalt that's got some washboarding in it that you cannot see can also give this symptom. Find your self a few known smooth and bumpy roads, try it out and see if that's causing the sensation.
Cheap advice, throw it away if you want.
Jan 13, 2012, 10:51 PM
#45
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All good things to check, unfortunately, I've done all of this, exhaustively. Some things to note.... I've put my stock springs on, and the vibration is COMPLETELY gone. None whatsoever. BUT, with a car load of people, it comes right back. I'm absolutely 100% certain, that is' ride height related. With Eibachs, it was quite noticeable with just me in the car. Swift Sports, less noticeable but still just barely there, with stock springs, it's gone. Load up the back of the car with a couple fat asses, it's back. Mind you, these vibrations are only under WOT and most noticeable in the higher gears (3 and up typically). I've already made one trip to the dealer. They could not replicate the problem. Next trip I'm going to take a ride with a few techs loaded in the car to show them specifically what I'm talking about. I have a good feeling that it's the rear half shafts. The CV joints are at an angle that is allowing them to resonate or vibrate under torque. As I've said before, just google "vibration under acceleration". Lots of threads with lots of different makes and models. VW guys experience it, Mini's, Hondas, all kids of cars. The only thing that frustrates me is that it seems to be a hit or miss things on the Evo's.
EDIT: and speaking of tight tolerances, with this much torque and thrust, a suspension dampening factor is a lot of art, esp when the mfr is trying to keep costs down -- we don't have coil-overs for what reason?
So the darn engine's torque could be creating an dynamic frequency feedback loop a bit, causing it to vibrate at the ranges of your WOT uses. Messing with springs or shocks could inject the randomness of results to get this. Might be different springs, even same make, might NOT do it. Ain't engineering materials grand?
Last edited by journeymansteve; Jan 13, 2012 at 10:54 PM.