vvt engine bottom rattle knock only on idle
 

I have got stock VVT engine with only forged rods (pistons are stock) it knocks/rattles only on idle, and it stops rattle after warming up to about 80-90°C temperature. It seems to rattle from bottom. I tried to disconnect belts so it is not problem with alternator, water pump or power steering .What should it be? Conrods bearings (it should rattle much more after warming up) , wrist pins or oil pump or anything else or is it normal for vvt bp-z3 engine?

https://www.youtube.com/watch?v=dwSm...ature=youtu.be

Piston slap? Hard to tell from your audio. Did you touch the bore when you re-rodded it? The fact that it goes away as it gets warmer is why I thinks it is so.

for contrast.

Bore is stock (83 mm diameter), also pistons. I only re-honning cylinders and installed new piston rings. Meassured compression, all four has got 12bars. Also checked cylinders with small camera through spark plug holes, no signs of any scratches.on walls.

What were your measurements after the rehone?

Did not meassure it after, it was only very soft, no meassurable..

This is engine sound after warm up, no rattle/knock. If the issue is piston slap/wrist pins or conrods bearing it should be much more louder after warming up isn't it?

https://www.youtube.com/watch?v=oKYR...ature=youtu.be

Piston slap can and often goes away as the engine warms up. You may have taken a little more off then you though when you honed it or it may have been close to out of spec and you broke the camels back. If it goes away and you can live with it I would see what happens for science. It could also be lifter ticking and I can't tell because the audio sounds like it is from the apollo missions on my old ass computer.

This is a bit of a stretch but have you checked the VVT components? My car is down until I get unlazy and pull my VVT system. It's making noise and the first time I heard it I thought it was piston or rod noise. Does it change if you unplug the VVT solenoid ?

Maybe yes, but if I unplugged vvt solenoid connector nothing happened - vvt is active only from about 1500 - 4000 rpm in my setup (pwm controlled by me221 ecu)

:drama: