timing chain rattle?

[timc83]

Hi all
Has anyone out there ever had any dramas with a vy ecotec (done 140000 km) with a rattle when hot at idle, but goes away when revved or at about 2000 rpm? I was thinking timing chain or ballance shaft bearings, but if it was ballance shaft, wouldn't it get louder with higher revs?
any help or sugestions would be great.

[IBLOWN]

Probably find its your lifters. Try an engine flush, new oil and a bottle of lifter free.

[timc83]

Yeah ive done that. Is a very weird noise, doesnt effect the performance or anything, and the hotter it gets, the louder the noise, its sort of like a tapping, grinding weird noise. i have ran the engine with out the belt off, and yes noise still there (shit). The engine has been sitting for a few months ( possibly 12).

[IBLOWN]

Well it could be the timing chain tensioner. When i built my motor i had a chunk of it in the sump... The motor never made any noise though.

If its not that then i hate to say it but its probably big end bearing noise.

[timc83]

Yeah. i dunno, it doesnt sound deep or low enough to be big end, i had a vl that spun a big end bearing, alot louder and deeper than this, the funny thing is it only does it when hot, at cold, you would not fault it. also, when stabbing the revs, as you back off, you hear a slight clicking/cracking noise up the top end area. bloody weird and anoying.

[IBLOWN]

Well you cant always get a lifter unstuck with lifter free. I still think its a lifter.

[jas98]

harmonic balancer? when u rev it goes away but at idle its noisy? just a thorght as it happened to a few of my cars and family commodores over the years

[FstStig]

Get a big flat blade screw driver and put it onto of the Rocker cover, put your ear to the screw driver handle and have a listen for any noise.