Thanks for all the replies.

So the dealer calls me today and guess what? Its the WATER PUMP! They replaced it under CPO warranty so its all good. Interestingly enough, when I asked for the bad part back, they wouldn't do it unless I paid them $150. I guess its going to be refurbished? I wonder how "new" my new pump really is....

This whole thing has got me thinking about doing some preventative fixes. Perhaps I should replace the cooling system hoses, coolant reservoir, and radiator (probably not all at the same time).

Also a funny thing about my loaner, a nice black on black 2010 (or 2009?) 335i sedan with sports package with 25k miles on it. I noticed that when I started it, it took a LONG time to crank. This happened several times...MUST be the HPFP! Then this morning I got that yellow half engine indicator (I think its Limp Mode). I had the same half engine indicator on another 335i loaner once before. BMW is great but this is getting ridiculous or I'm just unlucky

Thank God for the N52!

 

Same thing here last week. Replaced water pump motor.

 

how much would it be to replace a head gasket on a n52 / 54 motor?

10k? 20k?

 

Last Sunday afternoon the car displayed a low engine coolant warning message. I immediately pulled over and had it towed to the stealership to find out the car overheated. They replaced the radiator and thermostat and I was unfortunately out of warranty.

 

Exact experience here about a month ago, 65k miles. Water pump.

Interestingly these don't last too long compared to my other cars (I've have Japanese cars go 100k+).