300TDI drive belt

I replaced the drive belt as it was making noises, just as well as the belt was in a pore state when I inspected it, all the noise disappeared until recently when I start first thing in the morning sometimes it makes a short groaning noise from that area, could it be one of the pulleys and how do you tell which one if it is.
Thanks
Chris

Groaning noise could be pas pump.

You mean the Serpentine or Snake Belt.
The 'drive' is delivered by propellor shafts on a Defender.

With the belt off you can spin the ancillary pulleys by hand.
They should all be smooth to rotate and have no lateral (in/out up or down) movement, when you get a wrong'un you will know it.
Also spin the radiator fan there should be a little resistance when the engine is cold and be harder to spin when the engine is hot.
Again is should only spin and not wobble.

Make sure the fluids are topped up (water, oil and power steering) and start the engine.
Check that the belt is running smoothly around the pulleys and not touching any pipes or brackets.
Mind you fingers.
Get someone to turn the steering wheel firmly from one side to the other, 2 or 3 times, and listen for any odd noises.

Thanks I will try these.