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I've got a fresh built forged 25 in my 32. Standard head expect for super tec valve springs and tomei 264 cams WITH vct operated via a window switch.

The car has a very noticeable 'tick' to it, it's very audible at idle. My tuner told me it was the window switch which seemed strange?

Could it be a lifter? The tuner also noticed it was super noisy on first start but slowly quietened once it started to bed in.

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How thoroughly were the lifters cleaned out during the rebuild and rebled during installation?

Regular (per revolution) ticking will not be the window switch. if it is, and it is cycling that often, it will probably kill your VCT solenoid quick smart, so you'd want to look into that pronto. But you could check it yourself in 5 seconds by disconnecting the solenoid. If it keeps ticking, then it's not the solenoid changing state.

If the ticking is coming from a valve/lifter, you should be able to use a hose stethoscope to locate the noise to one part of the engine or another. Surprisingly useful tool is a 2' length of garden hose.

Edited by GTSBoy
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A mate had a similar thing happen when he built a 25DET with forged pistons. He described the sound as "piston slap" i had never heard the term before and have not heard of it since. His noise was only at idle and would become noticably quieter as the car warmed to running temp.

Yuh, piston slap is exactly that. Forged pistons expand more than cast as they warm up, so the cold clearances are greater and they whack the sides of the bores a bit when cold.

Only if they're shit!

A good piston should require no more than 2 thou piston to bore.

I'm feeling your pain dude....I have massive loud top end ticking noise for the first 30 seconds of cold start up... My motor had no lifter noise prior to Nizzpro re building it after I blew the head gasket. (It drove and held Boost perfectly with milkshake oil)

Yeah my nismo 740s are alot louder then my old 555s. Sometimes think its lifter tick but everytime I look its injectors

I spent ages cleaning my lifters, pressed out the old oil, soaked them in petrol for a few days then washed them in a parts washer. Cleaned all the stuff off then chucked them in oil for about 3 weeks while I was waiting to get the head back (and pumped them to get some oil into them)

Soakingdisassembled lifters in solvent or thinners works wonders, then scrub them with a toothbrush to remove all oil varnish. Make sure they are fully collapsed when reassembling. Seems to let them fill with oil much easier when you have the first startup.

OP you will know easily enough the difference between lifters and injectors by the noise they make.

My injectors do tick, but it's not that either.

It's a very loud, very crisp 'tick'.

Going back to engine builder tomorrow, my tuner keeps telling me to basically not worry about it, after 1000k's it'll 'bed in?' Sounds dodgy to me, a lifter should bed in as soon as its got oil pressure 10 seconds after first start up.

On another note car made 270kw on run in tune at 15 psi with a spike to 17-18. 681nm too. Can't wait to sort this problem and get the final tune done with 23-24psi

Do as suggested. Rev the engine and then when the revs are dropping off throttle and there is no injection occuring that will completly rule out injectors

it's not the injectors

It does it worse when cold, accel or decel it does it. It's a loud (audible from 20m's away over exhaust sound with bonnet shut) on idle does about 2 ticks per second.

I can head my injectors (sound like a 72 tooth ratchet) much more frequent and quiet.

I'm convinced this is a fked lifter. Going back to engine builder today so he can have a listen. I just hope nothing's damaged my brand new tomei cams

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