yup...i face the problem..but mine drop till 750 to 800....
i think what u need to do is to reset ur ECu...
unplug ur battery and leave it for 15 min.the plug in on again...this might help
my radiator fan was moving pretty slow, so i tot i recon it, but in the process of taking it out i broke the radiator as well since it is quite old already. so end up fixing 2 things.