2.5 thai motor bearing/ rattle/knocking noise on start up

Hello guys.
My 2.5 d40 nav has 170k on the clock. Im only owner and on cold start up it makes like a ratlle/ knocking sound (like a bearing) after a minute or two its goes away. The car drive perfect still and wondering if anyone could shed some light.
Iys booked into workshop end next week but and keen to know if i can find answer before.

Cheers and beers

there is a chance the issue could be one of the Pulley Idler Bearings, try spraying a good squirt of wd-40 on the bearing so the spray can get into it , let engine run for a minute then leave overnight and see how things sound the following morning. better option is to remove drive belts and start engine to test.
another cause could be the Alternator Bearing making this noise.
if its non of these then the issue might be oil related with either too thick of engine oil used and or the Timing Chain Tensioner could be on its way out as these rely on oil pressure to hold tension for the chain.

Its a thai 2011 so i think it the cold shut off built in to the ecu to protect the engine if timing chain is on its way out.

Knocking Noise

It could also be a Clapping noise from the "Rack" on start up!
my dose this often!

Do you get this noise when you start up later in your day of Travels?

Highway Man!

Nah i notice it more say when it sits over nite or all day at work. And ever so slightly sometime when its running. It sounds like crushing bearings. Im thinking it cant be anything internally in the donk as it still runs like the day i rolled of the show room floor

It ended up being a stuffed alternator.

good to hear it was just the alternator bearing at fault. common problem with any car.