600e cpu fan

[sole]

i've just upgraded my p11 366mhz 600e laptop to a p111 650mhz, i used power leap to enable the L2 cache and it all works fine apart from the fan, i'm not sure it's working correctly once it's running the fan is constantly whirring up and down, it's as though the fan starts up to run at full speed and then stops and then it starts again any ideas if this is normal, i also used the heat sink and fan from a 600x laptop