Bottom end noise??

[Jordo2]

G'day, I have a 91 3sfe camry. But When I start it in the morning and am warming up, it sounds like it has possible bottom end issues? This noise also resembles a diesel motor noise. However after driving for 10 mins and when the temp is at it's normal running temp, the noise is gone and the motor sounds fine. If it were bottom end wouldnt the noise become worse the hotter the oil got? Any help appreciated. Cheers.

[dirty hands]

if it knocks when cold starting its piston slap

if it rumbles it may be the mains as long as the noise

is the same as one revolution of the motor

if it is double the one rotation its the piston shaft bearings

if its faster than double its cams and lifters

one way is to fit an oil pressure guage to the motor and observe readings

or two... take the sump off and inspect the bearings by eye