Freshly rebuilt head with a tapping noise

chriscooke · 11-29-2012, 07:13 AM

Hi all. We have just rebuilt the head on my 90k s14a sr20det and it's got a slight knock which is a touch concerning.

The spec is as follows

Tomei 260 procams - Hydraulic lifter type
Brand new OEM Nissan rockers
Shims set to within 1 thou
BC springs + Retainers
Tomei RAS kit
ARP headstud kit
Cosworth 1.5mm MHG
Standard VVT sprocket
Uprated New exhaust valve guides
Valves cleaned and lapped
Valve seats ground iirc

Couple of vids, I'm not reving the car as high as it sounds in the vid btw

Can hear it at the end of this vid
http://youtu.be/bkIhUZNJ-uA

This vid makes it sound louder than it is but you get the idea
http://youtu.be/W4nnCydZs2A

I'm thinking possibly a noisy lifter as even though we have had them submerged in oil since their removal in July they ave been on their sides which I hear is bad?

The VVT sprocket has been kept in a shed :o so could it be this also?

Thanks for any help in advance

eric96ser · 11-29-2012, 10:10 AM

Even if you had the lifters in oil, I still would have bled them before installing.

chriscooke · 11-29-2012, 11:54 AM

This is what others have said.
I'm a bit of a noob with anything engine related other than bolt on parts so didn't think about it.

Does it sound like lifter noise?

eric96ser · 11-29-2012, 02:22 PM

They sound normal to me.

chriscooke · 11-29-2012, 07:40 PM

It's definately louder than it was before and a heap louder than my mates unopened sr is in his sx

10psigti · 12-04-2012, 02:58 PM

If u didn't bleed the litters I would bleed them and I think the tomei cams retain the vtc which is prone to fail so that can be the problem too

chriscooke · 12-09-2012, 08:59 AM

Thanks for the advice all

We took the exhaust cam out and bled the lifters and the noise is now gone

The car now has a misfire but I'm hoping that new coilpacks and plugs will solve that. I had hopped that we had made a bad job of earthing the coilpack loom but that seems fine