Ticking Sound On Idle - Rb25

[colourclassic]

My RB25 has developed a ticking sound which appears when the engine is warm and only at idle. Anything above idle and it seems to disappear.

It is *not* the injectors pulsing. In fact it can barely be heard when your head is over the engine.

You can hear it best when listening either below the engine or at the back of the front wheel wells.

I tried using a wooden dowel/long screwdriver stethoscope but couldn't isolate the origin of the sound.

I recorded a short audio clip from below the car which demonstrates the sound:

I first thought sticky lifters or a leaking exhaust gasket, but they would presumably appear worse when cold. This sound only appears when the engine is up to temp.

Ideas?

[Humbla]

Exhaust manifold gasket. :-)

[colourclassic]

If it was exhaust gasket I would have thought it would either be the same regardless of temperature, if anything get better due to metal expansion.

Any other ideas?

[Ben C34]

Exhaust leak.

Maybe from gasket, maybe not.

[Jim.t]

Did u end up figuring out what the noise was cause I have the exact same noise with my rb25?

[Diddle]

G’day, I Have this exact same noise in the video, anyone end up figuring it out? Same issue as originally described and tried everything OP did aswell. Only once warmed up, runs and sounds fine while warming up. Not an exhaust leak, all new gaskets + studs, washers and nuts for manifold and turbo. Also changed oil and filter plus trying different oil viscosities, hasn’t made a difference.  

Leaning towards lifters but due to it being alright on cold start has me baffled.
 

[Diddle]

Bump. Lifters replaced a few months ago and noise persists

[robbo_rb180]

Use to get a similiar noise on s14 with vct would make similiar noise. Could be nosiey VCT?

[Diddle]

VCT is working fine, it’s even difficult to locate the sound with a stethoscope. However definitely audible from under the engine as with OP’s video. Possibly worn bearings but it’s definitely not a knock. The sound can be heard while driving with the window down aswell when passing a barrier or other cars when the sound bounces back. Sounds like a little jingle bell weirdly enough. Any other ideas?