engine noise rebuilt 3.4 dohc

[z34gtp383]

hi guy's i just finished installing my rebuilt 3.4 dohc, in my 95 gtp, runs great lotsa power, but there is a clacking noise when you start to roll off as you go faster its gets louder, once you pick up speed it goes away, and on idle, its not there. could this be the lifters? i only have 120 kms on this engine so i cant run synthetic oil just yet, there is castrol 10 w 30.

thanks.

[SofaKingWeToddDid]

use 5 30, and i would pick synthetic when you get the chance. but 10 30 is too thick

[RedZMonte]

does it go away after a few min of driving? is it high pitched or low pitched? can you hear where its coming from when you open the hood? 10w30 should be fine..

S

[SofaKingWeToddDid]

10 30 makes my engine loud, thats all i know... when i started runnin 5 it ticks a little when you start it, but after a couple mins of warming up (more if its wintery cold out) the ticking goes away and all you hear is the fuel injectors if you pop the hood.

[z34gtp383]

never mind guys, bad news, this is a rebuilt motor and sad to say number 6 piston collapsed due to an airlock, this is my fault, not the builder, i thought i bled the system out 100% all the coolant looked good with normal flow, it was good for a few hours of running and when under load you can hear piston slap, so out it has to come again,hopefully i can get away with just a new piston and no reboring. will see.

[Schurkey]

The piston collapsed because of an air lock?

Huh?

[Dave96z34]

When you have an air lock you end up warping or cracking the head. Nothing to do with the piston.