Here is a video of my engine, it's making a weird noise.

http://www.youtube.com/watch?v=-XYrQNv6pKk

i thought it could be the mivec, i switch that to ON and the sound stays the same.
It's mostly when it's cold, and i didn't make that sound when i first built the engine.
The pistons have anti-scuff coatings, i'm wondering if they have worn off.
piston to wall clearance is 3.5thou

The sound only ever happens when there is combustions, i.e. if you rev up it will make the click/tick, but then as the engine drops back down it doesn't make the sound.
This rules out lifters.

I did a cold compression test, and came up with 161, 158, 162, 162. I will post up Hot compression results when i do them.

Any other ideas?

 

I would reccommend to get a borescope and inspect the glaze on your cylinder walls since your rebuild is fresh--That's probably the only way to tell what's going on or rule that out.

Sounds like an exhaust leak/valvetrain noise in the video!

 

yeah there is a small exhaust leak on the downpipe.
the sound seems to be coming from #1 area, on the backside (inlet side)

 

Have you tried hearing around with a stethoscope? I know my 2.3 is noisy as hell, especially when its cold. Once it warms up, it quiets down.

 

No not yet.
The thing is that it never used to do it. Then it's slowly become louder and louder. Just seems weird thats all

 

Mine use to sound sort of like that at least the best i can tell i found out that it was the valvesprings not being strong enough to handle my custom gsc 2.4 cams

 

thanks for the reply.
Was the noise you heard only on "combustion" ? i.e. didn't happen when you had the Throttle body closed?
I'm running stock Evo9 seats, retainers and GSC Beehive springs with S1 mivec cams.
As you can see, the "click" can clearly be heard at idle once the engine RPM has decreased from being Revved.

Cheers, Mike

 

hot compression is the same as cold compression (+/- 3psi)...

i'm stumped

Might be time to pull the head off and have a look
I wonder if it could be something as dramatic as a cracked piston, or worn out small end bearing...

 

Borescope before pulling the head mate.
Don't want to go to all that drama if its spotless underneath.

How do your plugs look?

 

that sound like a rod knock.

 

plugs look fine, running 9's denso's.
i'll try to track down a borescope.
I might take the sump off too and see what if there is anything noticable from the bottom.

Cheers, Mike

 

+1 hate to say so but thats what it sounds like to me

 

sound like normal cold engine piston slap to me.
2618 is very noisy with anything over .005. thing is since they take long time to expand to running clearance they wear quickly. your initial .oo35 could easily be .005 or higher at just 2-3000 miles.

 

any updates?

 

contact patch on the pistons was very small, think 1cm squared.
clearance was quite big.

But i had blasting media go through the engine and damage the head, cams etc.
So the noise could have been anything