Hi

When engine warms up, the engine noise increases very much compared to it's cold and just started.

why is it like that ?

Car is integra (LS/VTEC)
with forged pistons & rods.

oil is : castrol full synth 5w-40

 

What noise? Can you be more vague please?

 

Don't know what your noise is but maybe try running a thicker oil for starters

 

noise like coming from the cylinder head..
grinding.

 

maybe I can take a video of both cold and warm..
I'll try that.

 

ok, the thing is, it's impossible to understand the noise levels from the videos I took inside the car because the sound of video is too bassy, and I can't be outside as it's already raining.

What I realized is, the engine sound tone is just the same, but it's only much louder.

The noise level increase when hitting higher RPMs. Especially when VTEC engages, it's even louder.

The oil pressure is around 15 psi at idle when warmed up.
When it's around 25 psi before totally warmed up, the engine sounds much more healthy.

Maybe you can give an idea of what stuff I should consider checking.

Thanks..

 

Absolutely not. You have not even told us where the noise is coming from. Head? Block? Transmission? Near the belts? C'mon. All you keep saying is that it get's louder when warm and that it's a grinding noise.

 

ok, I'm %90 sure that the sound is coming from cylinder head.

sorry for the question, maybe it sounds like a bit stupid, but I can explain this much..

 

Maybe try runnIng a heavier weight oil bc you could have pressure in your bottom end but with such a thin oil and being a lsvtec you could be loosing oil pressure in the head in term causing grinding noises....just a shot from the hip with the minimal information you have provided

 

is there any way to check the oil pressure at the head ?

 

That may be tough to do. Trying thicker oil is prolly the easiest, or u can pull off the valve cover and check if you have any clear signs of damage/noise. Possible valve clearance issue.