Engine rattle on startup as If no oil pressure, more so on cold starts, was told was due to oil filter draining out as position of filter faces down.as if no non return valve. Have fitted OEM filter incase. Motor has had Complete cam kit fitted and reconditioned head. Rattle goes away fast but doesn’t seem right,and sure this wouldn’t be like this when new. Sugestions appreciated as hate hearing the noise.

Starting engine take a bit to kick over have changed fuel pump oil filter spark plugs cleaned air filter when over the top of it replaced almost everything please help!!. . .