I have been chasing an annoying rattle in the top end for a while now.
EF, totally stock.
New HLA's installed, and New 20/50 Oil, the rattle is still there.
Running straight GAS on a fully reconditioned head, AU HG, AU Bolts.

It sounds like it is ONE HLA/Valve/Spring or something is rattling ie. doesn't sound like 12 things rattling, just one thing whatever it is rattling.

It starts up from cold really quiet & then the rattle begins to build after a minute or so, and is constant at full temp, at idle.
The noise goes away with revs, and comes back at idle.
It's not consistent when cool and warm and floats in & out at these temps, but when hot is constantly there at idle.

Tensioner was installed properly when HG done, NO slack in chain.

My question, is if the oil pump is one the way out, will it cause all 12 HLA's to rattle, or will it show up in one or two of them first??
Also, how is the oil supplied in the rocker gear assembly? can these gunk up & get blocked?


The noise persists with 15/60 oil, and 20/60 oil, so going thicker does nothing.

Any ideas. It's p###sing me off big time.

all the shims go back in when the HLA's were reinstalled?can you pick where roughly it is? ie.. 1-2-3-4-5-6th cylinder?

I really sounds like like a shimming issue to me. you used the same rocker gear again i assume? maybe a slight variance in the HLA size that was in there?
Didn't drop a shim at all? The rocker gear is not hanging on any dowels?

Pull the rocker cover off and check for any play. if its really banging hard you will find the play by hand otherwise a feeler guage is your friend.

All shims were reinstalled.
Sound is from exhaust side, around 3,4,5 area.
Put same rocker gear back in - yes.
There were no dowels in there for the rocker gear to rest on. Should there be? EF I6.
No play in rocker gear.



I might try & get an MP3 of it. Anyone know how I could get this uploaded somewhere?

Thanks

Have you tried thinner oil's?
Thicker oil, less noise is not always the case, A mate of mine had a noisey EB, he'd always used penrite 20/60 I suggested thinner oil 15/40 and the noise reduced.

have tried 10/40 and still there
have not tried bang on the 15/40 you mention - might do this next change if it isn't fixed by then

Could be a PCV valve in the rocker cover rattling?