07 crd weird tapping noise

So ive started hearing a strange tapping noise coming from the engine area. Ive noticed it has come about since ive wired in the resistors for the egr blank. But what is strange to me is that its not a constant tapping sound, it dosen't do it at idle and it doesn"t do it under load. I can hear the ever so slight tap sound under light throttle after accelerating to my desired speed. Egts are normal and so is my boost. I thought it may have been the power steering pump, topped the fluid off and its still there. Blow by seems normal and ive got no bubbling coolant in either tanks. Ive checked the belt and the tensioner and they seem to be fine. Seems to run fine to me so im a little stumped for where to look next. I thought it may have been wheel bearing but its more of a metal tapping sound. Any suggestion people??

I should add its an 07 crd automatic ute with 252xxx kms

Does it have a butterfly in the pipe on the inlet to the intercooler? These are in place on the TD42 and should be removed when doing the EGR blank on a TD42 from what I've read.
It could be that moving and making noise??

i think the only butterfly is on the swirl valve (im still learning with the crd diesels lol) but everything ive read says nothing about removing the butterflys

Ok, it is possibly a different configuration with the 3.0. I haven't had any experience with them.
This is the guide for the TD42 with the butterfly in the intercooler inlet that I was thinking of for reference:
https://www.patrol4x4.com/threads/eg...m.56393/page-3