Help Identifying Possible Exhaust Leak

[Thor88]

Hello all,

I have a 93 GTR that has recently begun making a fluttering noise under load that sounds like a loud exhaust leak or something caught in a fan.

The sound is coming from the passenger side of the vehicle near the turbos and is only noticeable at higher revs.

It has no affect on performance, holds/builds boost normally, etc.

My first guess was a gasket from turbo elbow to down pipe, but the sound is still there with down pipes removed.

Vehicle is stock other than Apexi intake and Nismo down pipe.

I have searched but have been unable to find anything referencing a similar sound given that there is no affect on how the vehicle is running.

Any help narrowing down where the noise may be coming from would be greatly appreciated.

[KiwiRS4T]

Manifold gasket? Tried tightening the nuts/bolts?

[Thor88]

Manifold/turbo was my next guess, but I would have expected that to result in some change to performance/boost, the sound is quite loud which would signify a fairly large leak.

 

[GTSBoy]

Nope.  Lots of noise with no performance impact is completely normal.

[Thor88]

When removing the turbos, do I need to remove the oil and coolant lines? Or can I just remove turbos from the manifold and leave those attached? Tried searching but all results just state "remove turbos". The service manual shows removing all lines, but that seems like it would be unnecessary and complicate the process

Thanks again for the assistance

[rb30gtr]

On 4/19/2019 at 9:56 AM, Thor88 said:

When removing the turbos, do I need to remove the oil and coolant lines? Or can I just remove turbos from the manifold and leave those attached? Tried searching but all results just state "remove turbos". The service manual shows removing all lines, but that seems like it would be unnecessary and complicate the process

Thanks again for the assistance

It's actually easier to take the lines off otherwise you end up bending them around and if they are old/original like mine were they may be brittle, there are good videos/threads on removing the turbos available. It's a bit of a ball ache but can be done.

I ended up putting braided lines back on mine, but regret heavily not doing exhaust manifolds and dump pipes. So if you are getting elbow deep into GTR turbo's I'd suggest going in with a plan and parts. All gaskets, new turbo's, exhaust manifolds with studs and metal gaskets, braided line kit or new lines, dump pipes of good quality and new oil drain hoses.

You could get all the mech parts second hand as most people just go single turbo so there are heaps of Turbo/dump/manifolds available with low mileage to save cash.