Lifter Noise Or Knock? Rb25

[ossie_21]

I'm a long term member but haven't posted in a while, please be gentle . Can move onto another similar thread if need be...

No idea how to embed videos but I've uploaded the clip to youtube which shows the noise here Oh so it embeds itself these days haha -

Doesn't sound like it's spun a bearing but after a bit of investigating to me it sounds like it's possibly noisy lifter/s. I had the motor fully rebuilt a while back, it has forged CP pistons, Tomei poncams etc...I don't believe it has always made this noise but literally can't remember how long ago it started. It is only obvious on start up after initial warm-up higher revs, once you rev the motor higher it's pretty much drowned out by the noise of the exhaust.

I don't see it as a bottom end problem as the car runs fine, holds boost with no issue, doesn't misfire yada yada. To those on here more mechanically minded, would this most likely be lifter noise? After watching videos of spun big ends I couldn't compare it, but watching other lifter-related clips it sounds damn similar. When the motor was rebuilt I couldn't answer if the lifters were cleaned but to save people asking that, I'll go with no.

If it is lifter noise, what's the best/easiest way to determine it? Not hands on enough for me to remove/clean/replace myself, so parts cost aside any ideas on what sort of labour costs a job like this would be? Doesn't seem overly complicated but just time consuming, which is where workshops make most of their money lol

Thanks in advance Nathan

Edited February 13, 2016 by ossie_21

[GTSBoy]

Ever hear the saying "bangs like a buggered tappet" ?

That noise is the reason for that saying.

[ossie_21]

Ever hear the saying "bangs like a buggered tappet" ?

That noise is the reason for that saying.

Ah ok thanks. Would you reckon more likely seized & would need to replace them, rather than cleaning them & putting them back in?

[GTSBoy]

Dunno.

[ossie_21]

Thanks... ?

[XGTRX]

Lifter I would say. The noise is less prominent as the revs increase, where as with a spun bearing its more of a clunk at a certain rev range usually higher, but not always.

if you put a large screw driver with one end on your ear and other on the rocker cover you can usually isolate the noise. You can do the same with the car on stands and listen to the crank, just be careful. Hope this helps.

[Ryno]

You could try adding a bottle of ZX1 to the engine oil... It all but eliminated any lifter noise from my RB25

Edited February 14, 2016 by Ryno

[AngryRB]

how many km's has the head done?

[jiffo]

At about 10 to 12 seconds I can hear lifter coming/going, but there's also another deeper knock which to me says she's not too good.

Sounds much worse after the free revving.

[ossie_21]

Thanks for the replies guys, going to do some investigating tonight. Have seen the screwdriver trick mentioned so will give that a go & see if I can pinpoint it.