diagnosing a blocked radiator??

[A G Wood]

James- If you've got little or nothing to loose, (and I see you've tried a degreaser and dishwash powder) I've seen a recommendation for clearing oil/grease blocked radiators [in the particular case of 'overuse  of the water pump greaser'] whereby the cooling system is filled with kerosene instead of water and the engine run until warm, then the cooling system is drained and refilled with a 'strong solution' of washing soda and the process repeated. No mention of damage to rubber parts, and although kerosene isn't cheap here anymore and I guess its the same in the UK, washing soda is. Might be worth a try? Also do you have 'Alfloc' brand cooling system products over there-they used to make an awesome high pH cooling system cleaner in powder form which you premixed with water that gave some pretty impressive results in some of the junkyard refugees I've dealt with in the past.