Hunting a vibration r32gtr

[Gtr_fan]

Ok I have a “messing with my head” problem!

Recently re-registered my 32gtr after a few years. Changed all fluids and replaced engine and gearbox mounts. Really don’t know how long passenger mount was broken for.

 

I now feel a vibration in the seat when hitting 0.3 bar boost and get worse as boost build / power increases.

 

Now this problem only happens when the car is warm/hot. 

I.e after brief warm up it will drive for 10 or so minutes beautifully under boost / strong acceleration. 

 

Then after a while vibrates under boost.

 

- I have run in rwd by removing the fuse and problem is still there.

 

- recently had new tyres balance and alignment which was fine. Same mechanic inspected centre bearing and said looks fine. 

 

Mechanic also couldn’t feel the problem as does not start to happen until after driving for a while.

 

-engine and steering are smooth. Engine knock always low under 30.

 

vibration is not speed sensitive as all speeds highway etc are smooth under 0.3 bar.

 

The problem feels like it’s coming from / sending vibration to rear left.

 

I see my rear turbo is leaking. 
 

there is no bearing / turbo whine. However under high boost 1 bar I can hear a fast fluttering sound.

 

Ideas??

 

Could a bad turbo cause a vibration felt in the seat?

 

Any help is much appreciated.

Edited October 10, 2020 by Gtr_fan
More info

[GTSBoy]

Won't be turbo. Might be gearbox, input shaft bearing or some other bearing further back. If it's only felt once there is significant load, it implies bearings that get side loaded under torque input.

[Gtr_fan]

Thanks for that. It is doing it after warming up which is throwing me. 
 

could a wheel bearing cause this. I remember left rear bearing / hub years ago was a bit noisy but then stopped. 

[GTSBoy]

1 hour ago, Gtr_fan said:

Thanks for that. It is doing it after warming up which is throwing me. 
 

could a wheel bearing cause this. I remember left rear bearing / hub years ago was a bit noisy but then stopped. 

I very much doubt it. Remember what I said about "it implies bearings that get side loaded under torque input"?

[Gtr_fan]

41 minutes ago, GTSBoy said:

I very much doubt it. Remember what I said about "it implies bearings that get side loaded under torque input"?

Thanks heaps. I will have a further discussion with my mechanic and go from there.?

[GTR32 Jeff]

Does it lose any power when it vibrates? Is it a sound or just a feeling? Something moving around when it squats, or holding speed on a steep hill shows the same?

Could be a dead exhaust bolt/gasket or similar, otherwise I would check for stupidity like swaybar links near the exhaust, wheel nuts etc.

If not something little, after you get home and its doing it jack up the rear by the diff and spin the wheels by hand and listen/feel.