The fans do NOTHING once u are upto speed. The thing to do is to work out when it's running hot. Get on the motorway, stay at 70 for a few mins, and see what happens. If it stays cool, then the rad and cooler are fine - it's a problem with the fans. If it is STILL running hot, then u have more serious problems - maybe a headgasket.

Also, the slope seems to have gone on the new cooler - thats bad as it promoted even airflow through the cooler.

Rick