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Location:
Canberra
Registered:
May 2002
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 vibration from 3TGTE
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Wed, 15 May 2002 12:16
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Hey all
i have a problem with some sort of harmonics/vibration with my 3TGTE. it occurs from 3500rpm to redline, and you can feel the vibration through the whole car.
The engine has been balanced when rebuilt 8 months ago, and started out fine, but has progressively got worse.
any ideas?
Thanks in advance
Phil
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Location:
Sydney
Registered:
May 2002
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Re: vibration from 3TGTE
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Thu, 16 May 2002 09:58
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Phil, do you have a 2 piece tailshaft??? if you do check the centre bearing!! They can cause bad vibrations in the driveline which can appear to be from the engine.
Does the engine vibrate when revved in neutral?
Also check your engine mounts, diff ,axles and axle bearings.
If the engine was that bad it should have chewed the bearings out by now and shit itself!!!!! 
Jamie
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Location:
Canberra
Registered:
May 2002
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Location:
Tasmania
Registered:
May 2002
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Re: vibration from 3TGTE
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Fri, 17 May 2002 03:30
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I have a problem in my 2TG from 5500rpm and up. It won't want to rev past 6000rpm. I think it is a colapsed valve spring. I also have valve tapping noise at lower rpm.
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Location:
Newcastle
Registered:
May 2002
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Re: vibration from 3TGTE
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Fri, 17 May 2002 03:44
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Mate I agree with Jamie (MRTA22), check/inspect everything you possibly can before making a decision.  It could be something else that you would least expect. Also had a vibration in my car after mounting the new intercooler and it turned out that there was not enough flex in the intercooler pipes/hose.
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Location:
Canberra
Registered:
May 2002
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Location:
Newcastle
Registered:
May 2002
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Re: vibration from 3TGTE
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Mon, 20 May 2002 04:43
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Yeah it dose sound a little noisy at idle when oil pressure is low, but when i give it a few revs or its under loads it sound fine. If the oils a thin grade or not able to take the temperature this may make it sound a little loud. Also keep an eye on your oil pressure gauge to make sure that it has quick response to revs and good oil pressure. Had my hole engine rebuilt about 8 months ago and only have about 3500kms on the engine and i still listen for every noise.
Neil.
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Location:
Melbourne
Registered:
May 2002
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Re: vibration from 3TGTE
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Mon, 20 May 2002 07:54
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Phil,
I hope it is only a matter of transfer of normal vibration to your intercooler.
I've heard that 3TGTEU's have a tendency to sheer flywheel bolts. If they are starting to stretch i'd imagine you'd notice vibration (in neautral). Having a flywheel sheer off sounds pretty terrifying to me - I think you'd notice vibration then 
As I recall you have forged pistons. Where these matched in weight to the factory pistons? Or did you get the crank rebalanced for the new pistons? If the later how much did it cost?
Cheers
David
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Location:
Canberra
Registered:
May 2002
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Re: vibration from 3TGTE
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Mon, 20 May 2002 08:53
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SHIT! I wish i knew they commonly throw flywheel bolts! anyone else had this problem?? I had the flywheel off just a couple of weeks ago to get it re- balanced, thinking it might be a part of my problem, i could have changed the bolts then!
I have got forged pistons, they are a bit lighter than the factory cast ones. What do you mean about having the crank balanced to the weight of the pistons?? I thought the only way to balance a crank was on its own, or with its associated rotating parts bolted to it, such as flywheel, clutch, harmonic balancer etc. thats how mine was balanced. For that it cost me $165.00. I cant picture how different piston weight would affect vibration. What happens when you flycut valve reliefs in the top of pistons? what if you have different composition rings, or different weight gudgeon pins?
CHeers
Phil
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Location:
Melbourne
Registered:
May 2002
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Re: vibration from 3TGTE
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Mon, 20 May 2002 15:02
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Phil,
The way of overcoming fly wheels sheering off - apart from the obvious (i.e., having them balanced, using hi-tensile bolts at the right torque etc) I've heard of dowel pinning the fly wheel.
Yes to my suprise as well I would have thought that cranks would be balanced on their own but there is this matter of "bobweighting". I have this book on engine blueprinting which shows "bobweights" added to the crank to simulate the weight of reciprocating mass of piston with rings, rods, bolts, pins. I'll dig out the book and post some extracts/send you some scans. Maybe its all bullshit? I recall that with lighter pistons it is the case that the counterweights are made lighter making for a lighter reciprocating and rotating mass. The lighter rotating mass makes for faster response (as does lightening flywheel - 'external balance').
All reciprocating components need to be matched. As rods have both rotation and reciprocation each end of the rod is weighed sort of seperately on a special balance.
I'm speculating now...For ever action there is a reaction... but the counter-weights on the crank are at different lengths along the crank and different points gets loaded on the power stroke - so does the crank twist - just a bit???
I'm no mechanic or engineer but can imagine a few grams reciprocating some 70/80mm (stroke?) could add up to quite a weight.
Just some thoughts.
Really hope it's your intercooler rattling
Cheers
David
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