Being 10 years old, chances are the radiator needs some attention. In fact, make that the whole cooling system. I would pull the radiator out, and check the cooling fins in the lower front half of it. These are "out of sight, out of mind" but quite often have deteriorated so such a state they are no longer efficent. If the fins are flakey to touch, they crumble away, then its time for a recore. When its out, give the whole cooling system a good flush with clean clear water, removing as many coolant hoses and drain cocks as possible. I remove the thermostat housing and thermostat so water can be flushed directly through the block. There is a drain cock at the rear of the motor, under the turbo. Remove this and backflush through it. Check the oil cooler coolant lines (If fitted). If a recore isnt necessary, a core ream may be. A radiator shop will remove the top radiator tank and push a flat rod down through each radiator tube, clearing out anything blocking the tubes. Its amazing how much garbage gets stuck in them, reducing their efficency.
Then there is the viscous fan, it could be cactus. Im sure someone else here can educate you on how these work, I have changed to dual electrics.

Cheers
David

Growing old is compulsary, growing up isnt, and
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