RB25DET Neo Engine Noise

[Dyzzii]

Hey guys

i made a post in the past about a strange noise my motor has been making on the dyno. It is only heard through the knock sensor when listening in to it, and starts bang on 5krpm and stops around 5.5k every run without fail. Almost sounds like a very fast ‘ddrrddrrddrrddrr’ (best way i can describe the noise on here). Cannot be heard just listening normally.

The ECU is picking this noise up and pulling timing occasionaly because of it, but me and my tuner are stumped as to what it is. It appears to be coming from somewhere in the head area of the motor (at least thats what it sounds like).

I’m coming here to look for advice on where to look. The cambelt has just been done with all new pulleys is etc, and has been done properly as I was lead to believe that could be a potential culprit. Disabling the VCT does not affect it, noise is there whether that is on or not. Has anyone else had experience with this or any advice on what it could be? Tuner is thinking it may be my intake cam gear, but has never heard of them failing before. Should also add compression is fantastic on all 6 cylinders, and car only has 105,000kms.

Any advice and input is much appreciated!

 

[wildeagle44]

Only under load only or free revving too?

[Dyzzii]

Am unsure of that. I can’t hear it as it can only be heard through the knock sensor. I assume he will have only done runs with it under load, but probably better to assume it makes it all the time. What were you thinking?