Why my 2006 BMW only overheats in the morning?

Yes, it is an issue- if you overheat your engine you can damage it severely and that BMW engine is expensive- please try to fix whatever is wrong before this happens- check your cooling system for leaks- it also could be a bad thermostat or sensor- or, or, or , or- if you do not feel competent to maintain your BMW find a good, honest, mechanic who can do it for you- if you don't have the money to pay a good BMW mechanic, find a way to get it- or trade it in on a Toyota-

I appreciate the quick response everyone!! The expansion tank does show some leak at the cap area. And From all the suggestions received, could it be where the thermostat is not opening fast enough and causing the pressure to build up and the cap at the expansion tank is the weakest point causing it to leak out. Doesn't BMW have an automatic shut off so it will not allow the vehicle to accelerate? My wife has been driving like this for awhile and it shows no sign of damages. Not that I want to continue doing this but do you think further damages could occurred even if it's drive able and damages are not noticeable?

Hello Naod247, I know it’s been several years since you posted but I could I please ask what ended up happening? I have same car / year (2006 325i) and the exact same intermittent problem. Considering same possibilities of water pump / thermostat / head gasket leak. Any insight greatly appreciated.