[QUOTE=bcredliner;1013615] For the next 20-30 minutes the fan will come on for about 15-30 seconds about every 5-10 minutes until the radiator temp stays below the thermostat setting.

That's an item to remember when you're inspecting something under the hood after a run. A "Caution Fan" label comes to mind if you know what I mean, just to help you remember. At least it would help me remember, because your memory is the second thing to go...I forget the first!

It's been great to follow your progress on this and the information is appreciated. When I worked for a class VIII truck manufacturer, we considered a four electric pusher fan array to replace the mechanical fan, but determined the cooling requirements of a 12L diesel engine under full load would require some massive electric motors on those fans.

I don't know if you do any towing, but it will be interesting to see how your cooling performs transitioning from a high load operation period like a hard highway run in one of our 100+ degree days to idling in traffic. Looking forward to a follow-up next summer!

2002 X5 3.0 264,700 miles
2004 325i 116,500 miles