fan blasting away on start up

[gamestaffords]

Hi back again
 when i start my car the fan comes on full speed for about 30 secs,,
anyone no why? im hoping its not the control unit under the batt as there so dear...
thanks in advance ross

[Mr_Orange]

Do you think this is the radiator fan? Have you popped the bonnet and had a look? It's more likely the aux air pump, that warms up the cat. They do exactly what you've described at start up and can get noisy over time as they start to fall apart.
Start it up and go look see ;-)

[gamestaffords]

thanks mr orange for your help on both threads

[Mr_Orange]

thanks mr orange for your help on both threads

No worries. Was it the Sai pump?
Its just good to share what's been learnt over the years ;-)