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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Tue, 17 August 2004 23:17
 
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Oldcorollas - mate sounds like an interesting test. Do you reckon a microphone would pick it up though , its not really a noise? Willing it give anything a go though 
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Location:
Sydney
Registered:
May 2004
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Re: Engine vibrations, narrowed it down.
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Tue, 17 August 2004 23:23
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I had a vibration once in my st162 right after i changed the gearbox. just got under the car and started banging things. your problem sounds a whole lot more complicated tho.
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Location:
On your mum!
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 07:37
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Are you sure that the uni joints are in good working order?
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 10:34
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Yeah original was thinking uni's but it happens when the car is stationery, which I think rules out driveline stuff.
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 11:22
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OldCorollas - I recorded the engine sound in Goldwave.
Kinda unsure what to do with it now though??
Its like a sound graph kinda, and like from idle up to 3500rpm or so there isn't a lot of difference, lots up little ups and downs but overall its quite level. Then around 3500 + it increases a lot and then stays level, then when you back off and hold it at a rpm it dies back down.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 11:26
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maybe... if you put a mic against the floor perhaps, or anywhere you can feel the vibration..
if it is at crank speed, and you rev motor to 3600rpm, thats 60rps, so 60Hz, which should be within the range of a mike...
dunno, is worth a go perhaps  'specially if no other answers are forthcoming...
Cya, Stewart
[Updated on: Wed, 18 August 2004 11:39]
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 11:29
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Mate what would 5000rpm be? As in my sound file I know exactly where that is.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 11:38
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heh heh, i have message lag 
5000rpm
5000/60 = 83.3 revs per second (hmm i farked up previously, i'll edit it)
= 83.3Hz
= 12ms per revolution.
thats 6ms per ignition event, and 24ms per engine cycle.
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 11:42
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Here is a picture of the sound file
I've highlighted when the vibration starts up to 5000rpm where its held for awhile.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 11:47
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an you expand the time scale so you are seeing say... 1 second only? or maybe half a second?
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 11:54
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I exported it to an mp3 file 1mb, can I email that to you? if so, whats your e-mail addy?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 12:21
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Emailed
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Engine vibrations, narrowed it down.
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Wed, 18 August 2004 13:04
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hmm, i dunno if i'm doing ti right, but with 100Hz lowpass filter, i get:
the time of one wavelength is approx 0.011, so thats around 90Hz, or 5400rpm... could be 500rpm out tho...
as for finding the vibration.... any ideas anyone? we can run a bandpass filter to look for specific frequencies?
or high or lowpass? or noise reduction??
Joel, any idea if the vibration sounds at engine speed? or less or more?
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations, narrowed it down.
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Thu, 19 August 2004 00:38
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Hmm this is all very unknown teritory for me 
I can't really tell if its at engine speed or not, the vibration gets more harsh as the RPM goes up though. Like around 3500rpm you can hold your hand on the plenum but at around 5000rpm it'd be hurting your hand to keep it there.
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Tue, 07 September 2004 12:19
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Howdy, well the rebuild has started! I pulled the engine out last night and started to strip it down tonight.
So far i've only got the manifolds off and the sump. There was small bits of metal stuck to the oil pickup. I undid the conrod bearings but they all look ok. Maybe it's come from a big end.
Anyhow will find more soon I hope ..
Cheers
Joel
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Location:
Terrigal
Registered:
May 2002
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Location:
On your mum!
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Tue, 07 September 2004 12:31
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If you have hammered a big end then you will need to check the crank pin for ovality and the conrond big end (they will usually be duck egged from the pin hammering at the inside).
Good luck
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Wed, 08 September 2004 11:46
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I finished stripping the engine down tonight.
All bearings look fine. Not sure what else to check really. I cannot see anything visably wrong.. But suppose you might not see a bend in a rod etc.
One thing that I'm not sure if its normal or not but the shaft that runs the 2 gears on it to link up the upper and lower timing chain. Well once the gears were off you can move it in and out 5mm or so. Maybe this is normal though? But if not then suppose its possible the lower chain was moving in and out slightly.
Anything else I should be checking now its all apart? Or just drop bits into Graham Wilkins to check out?
Cheers
Joel
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Location:
Castle Hill, Sydney
Registered:
February 2004
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Wed, 08 September 2004 12:01
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Hmm thats interesting that your dummy cam thing didn't move in/out.
With the plate on mine it moves. Cant remember first time when I built the engine if this happened or not. Wasn't really looking for problems back then.
I reckon that moving in and out and moving the timing chain around could cause vibrations.
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Location:
Castle Hill, Sydney
Registered:
February 2004
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Re: Engine vibrations - rebuild started
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Wed, 08 September 2004 12:08
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HMMMMM
if it shakes the hole engine, and even the car, its gotta be mroe than a dummy cam slapping around a little!
ide put all my money (negative $220 and a cam chain tensioner)
on saying its crank related
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I supported Toymods
Location:
south of the big smoke
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Wed, 08 September 2004 12:30
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i think something is trying to tell ya get rid of 3t and finish 3s
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Location:
Sydney
Registered:
June 2004
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Re: Engine vibrations - rebuild started
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Wed, 08 September 2004 13:37
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mate a movement of 5mm is HEAPS! movement of any component in the block shouldnt even reach 1mm. the crank from most forwards position to most rear position shouldnt go over .8mm (estimate) and then when car is at normal op temp there is no real movement.
wow 5mm is really alot there mate, when you say dummy gear your talking bout dizzy gear right?
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Thu, 09 September 2004 00:06
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I think its what the dizzy in a 3TC would run off.. Where with 3tgte it runs off the cam gear.
So in the block there is a shaft that does run a blanked out gear that yeah probably for dizzy. On the front is 2 gears for the upper and lower timing chain.
When I took the gears off you could move it around heaps. There is a plate at the front of it to hold it into the block, but it doesn't stop it moving. I am wondering if there is meant to be some clip to help hold it.
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Location:
Sydney
Registered:
June 2004
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Re: Engine vibrations - rebuild started
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Thu, 09 September 2004 07:45
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actually from the 3TGT repair manual that gear should run the internal oil pump. from the manual that gear has a chain running to the crank, controlled by an oil tensioner. the other cahin runs to the cams controlled by the external tensioner. and runs the oil pump.
well thts what i can gather from not being able to read japanese!  its like a picture book to me 
now if that is the gear you are referring to then a play of 5mm is a no no from what i know bout mechanics, but cause i cant read the book i cant tell what the play threshold is.
let me know if that is the correct shaft your talking bout?
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Thu, 09 September 2004 10:33
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Yeah thats the right one mate. Though i've been told from a reliable source that the movement is normal, but when you put the cogs on the front that stops any movement.
I'm dropping crank, rods, pistons into Grahams this saturday.
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Location:
Castle Hill, Sydney
Registered:
February 2004
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Re: Engine vibrations - rebuild started
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Fri, 10 September 2004 01:48
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now that i think about it, once the plate is on it holds the cam in the block (stops it coming out, but nothings stopping it from pushing in, until the cogs are on!
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Fri, 01 October 2004 02:26
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Finally found the problem! There was a bent rod. I'm actually pretty happy about this which might sound odd.. But at least I know the problem and now can fix it.
Now on the hunt for some 3tgte rods....
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Location:
Sydney
Registered:
June 2004
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Re: Engine vibrations - rebuild started
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Fri, 01 October 2004 02:35
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good stuff, good to hearwas something small too... hey joel try ROD, i think he has but not too sure. iv been getting some motor parts off him so try there first
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Location:
Terrigal
Registered:
May 2002
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Re: Engine vibrations - rebuild started
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Fri, 01 October 2004 02:47
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Yeah i've sent Rod off an email ..
There is some guy selling some 3tgte bits including rods/pistons in QLD in the for sale section. I've expressed some interest in just the rods so hopefully he'll get back to me.
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