Low coolant level word to the wise (which I was not)
 

So I'm kicking myself. After a 8 hour plane flight from Germany, an hour in customs, and an hour into my drive home from NYC in 95+ degrees, the low coolant warning came on ('06 X5 3.0). I was exhausted and only had 40 minutes til home so said to myself I'll just keep and eye on the temp gauge and find a gas station if it warmed up at all. 20 minutes later, all was good, no change in temp and almost home. Must be a small leak - just a little low. Wrong.

10 minutes after that, Bing! Temperature spikes, I get the warning and I pull over. Walk a half mile to a gas station for coolant, half mile back, and it immediately drains right on the ground. Still too far to tow it home I find a reputable shop nearby. Cracked radiator. Needs new radiator, expansion tank, a hose, and thermostat. I would have done it myself, but needed the car ASAP. I think I got a good deal on labor ($250), but not on the parts ($800+).

Anyhow, I was stupid. If I filled it up when I got the warning, it may have just been just a DIY expansion tank replacement when I got home. I'm sure most of you are bright enough to not make my mistake, but for those of you that even slightly consider driving with the low coolant warning, Don't do it!

Top off anything that triggers the warning.

In your case, I don't think you can savage anything even if you fill up the coolant. The system is under high pressure so with more coolant in there, it might blow out even faster. I think low coolant is not the cause of the crack radiator.
Price is high on both labor and parts.

Good thing is you have it back on the road now.

Thanks - I guess this makes me feel a little better that maybe there was more to the cooling system issue than just low coolant, but does not excuse my stupidity.

Agreed - I feel lucky I didn't do any further damage outside the cooling system. I was also happy this shop was nearby even if it was costly. To tow it all the way home and diagnose would have added tow fees and time to ship parts that I unfortunately just didn't have.

Anyway hate to say this but the coolant system repair is preventive maintenance item. If the vehicle has 100k or 10 years old its time to refresh and upgrade. I am sorry to hear about your situation but cooling system is a known preventive maintenance item. When I bought my 4.6is in 2015 it had 92K and the first thing addressed is the cooling system. All the houses were changed new thermostat, the radiator and coolant expansion tanks had been replaced but I wanted piece of mind. When I did the timing guides and cover gaskets I changed the water pump and installed new valley pan gasket. My X is coolant leak free and oil leak free.

I saw similar recommendations on this site when I first bought my X in March and cooling system maintenance was on my list. It does have 149k miles, but I saw a coolant flush and water pump replacement on the Carfax a few years back. So in the past few months, I focused on the AT fluid/filter, diff fluids, transfer case fluid, fuel filter, brake bleed, and spark plugs. I did do a coolant drain/replace about 4k miles ago just because it was quick and easy, but didn't notice any leaks at that time, nor changes in level since then.

I'm not saying I shouldn't have addressed the coolant system sooner, just that I was prioritizing my preventative maintenance. Live and learn I guess.