[adamsaiyad]

Can any one with experience tell me how do you tell if the dual mass flywheel isnt balanced ?
Or any flywheel experience with a GTR34 with a getrag box ?
I have a problem where the whole car shudders and vibrates at revs higher then 6000rpm and its pretty bad ?
what other possibilities are there i have checked engine mounts and all are solid and tight ?
what else could cause this vibration at revs that high ?
Prop shaft ?
Gearbox mounts maybe ?
im desperate as i have a new engine and have run it in and dont want the car to explode again cause of the flywheel ?
please can some one help?

 

[R.I.P.S NZ]

Sounds more like a driveshaft or hanger bearing to me.

Rob

 

[fourtoes]

Funny my DC2 is doing somthing very similar to this right now too!

bob

 

[adamsaiyad]

a drive shaft or hanger bearing weird ??? what is a hanger bearing if you dont mind me asking ?
If this was a problem with the flywheel should the engine do the same thing when reving stationary at high rpm though im very hesitant to rev the engine at such high rpm with out a load on it ?
Should i try this have the car in neutral and see if it does it when reving with the clutch out a few times and then with the clutch in a few times ??

 

[Asim R32GTR]

a drive shaft or hanger bearing weird ??? what is a hanger bearing if you dont mind me asking ?
If this was a problem with the flywheel should the engine do the same thing when reving stationary at high rpm though im very hesitant to rev the engine at such high rpm with out a load on it ?
Should i try this have the car in neutral and see if it does it when reving with the clutch out a few times and then with the clutch in a few times ??

Hanger bearing will be the middle bearing on the propshaft.

I would imagine the flywheel would have to be WAY off balance to cause your problem.

Rev the engine, no problem.

Most likely it is a propshaft problem. What you could try is undo the 4bolts that connect the propshaft to the gearbox, turn propshaft 90 or 180degrees and bolt it back.

Asim

 

[fourtoes]

What about a FWD car?

bob

 

[Austrian GTR]

Funny my DC2 is doing somthing very similar to this right now too!

bob

That's the revenge for the bad fuel you gave him last time... :chuckle:

Have you checked the bearing to the left of your gear box (passenger side, the longer drive shaft, underneath the oil filter) for play or if it's worn??

Had this once on my DC2 causing some annoying vibrations...

Leo

 

[fourtoes]

Ha ha, i dont work on the DC2 Leo buddy, if I did i wouldnt have enough time in my life to eat or sleep! (or have a girlfriend!) Last time i took it to Honda they replaced one of the bearings in the gearbox, cost me about a grand in the end, hoping its not another!

Cheers for the info Leo mate.

bob

 

[Austrian GTR]

Oh man, you're really getting old...
... DC2 is very easy to work on compared to the GTR. You have far more space in between to reach tricky bolts and nuts

Tell me next time you're in truoble with your DC2 or when you need spare parts as a friend of mine is a real genius on that cars and he also has loads of spare parts lying around (guess you could build five or six complete cars out of them).

Would never pay a workshop a grand for something I could do on my own :smokin:

Leo

 

[kismetcapitan]

How about the obvious...the front damper? I'd get on that most Ricky-tick or you will break your oil pump.

 

[adamsaiyad]

I am using a brand new 900bhp Ati damper fitted by myself was i supposed to use hot water etc to fit or just put a bit of engine oil and torque the bugger to 450-500 nm ?
i got a torque wrench that size used on trucks etc hung off it practically and it clicked or bent should i say rather ith 5 guys holding the motor on the bench.
and three guys holding the flywheel with a tyre lever.
hmmm makes me wonder if ati would make a damper that would do the reverse and make a vibration as apposed to damper????
any one out there with some more input ?
thanks for all your help though guys.

 

[adamsaiyad]

Big end bearings was mentioned by some one on the forum .
Could the vibrations i was getting at high rpm cause my big ends to fail after 1200kms ?
Oh man my third engine rebuild if thats the case and im fretting i cant believe this.

 

[adamsaiyad]

any more info

Please any one had a mechanic listen one of the two i need to listen and he recons something is loose in the engine or could be the flywheel making the noise ?
But says it sounds more like bearings making the noise.

 

[kismetcapitan]

did you try unbolting your driveshafts? I'd unbolt both, one at a time.

Rev the engine and also check the damper with a strobe, see if it wobbles. If the woodruff key is worn, it could cause problems.

You had this problem before when your big ends failed, and then after rebuilding it still exists? Who built your engine??

 

[adamsaiyad]

Hi Kismet, thankyou for your response
I did not have the engine rebuilt this time i got a brand new engine from nissan japan Nur spec, had the flywheel balanced and because its a dual mass i fear that it may have damaged the bottom end as its making a rattle noise when i rev at stand still.
Ive only done 1200 kms on the engine and cant believe that the bearings would have failed already.
I have a unbalanced dual mass flywheel that i think is causing the bearings to have failed.
Why would you recommend taking out both drive shafts and then reving the engine ?
i have tried reving the engine in neutral and the rattle is there and also the vibration at high rpm.

Hope to hear from you soon thankyou for your advice .
I will be rebuilding the motor should there be a bearing problem etc.
I dont have much experience but i know alot and will put it into practise last time some one built my motor for me i had a conrod go through the block so this time its all on ME ME ME !!!

 

[kismetcapitan]

unbolt both driveshafts to make sure its the engine and not the shafts. Then rev.

Spun bearings rattle at 3000rpm and up, where is your sound happening at?

When did this problem start? What were you doing when it started?

The car shakes violently even in neutral and you rev over 6000? That does not sound good...

 

[rb30r34]

Get rid of the dual mass flywheel. I have seen them play up in every type of car I have seen them in.

 

[adamsaiyad]

I was starting up the engine to feel the vibration from the flywheel to see if it was coming from the flywheel or from a drive shaft.
So i went to front of the engine and used the throttle butterfly control arm to rev the car and when i started reving the engine i noticed that it was making this weird rattling noise .
Its starting at about 2000rpm and follows through till high up in the rpm range.
It only makes the noise on acceleration not on deacceleration.
Can i ask how would a drive shaft cause this rattling noise even if the car wasnt in first ?
Could this be detonation maybe that is happening in all the cylinders ?
Should i take the timing back a little and see what it does.
I also have a hard time starting the car when cold and hot i have to place my foot on the throttle slightly and open her up a little to get her started?
Why could this be what signs should i be looking for maybe shagged fuel pump ?
or possbly something else.
I have changed the fuel filter.