I've been searching the forum for what this hose is but can't find anything. It's the hose below the coolant temp sensor. Coolant is spilling out from that area right on to the belt and being flung all over the place.

I have the N52 engine, if that helps clarify.

Any help is appreciated, see attached pics.

 

Have you checked on realoem.com?

 

I did look on there but could not identify exactly which hose I needed. I have since found a video of a guy replacing this exact hose. It is a Cylinder Head Thermostat Hose and is part #11537544638 in case anyone else is trying to figure it out.

 

For an n54 but might be the same...ask the seller...
Look at this on eBay Water Cooling Thermostat Hose For BMW 128 325 328 330 523 525 530 Z4 E90 E84 E86 | eBay

 

Look at this on eBay BMW 335i 11537541992 OEM WATER HOSE FITTING REPLACEMENT ALUMINUM 6061 | eBay

 

I've been trying to replace the hose attachment part for that hose--just under the coolant temp sensor. Can't find anything on it. Did you ever get your problem solved? Any data would be helpful.

 

Nevermind--guess I couldn't see the whole thread before. Thanks--was really having trouble finding this part!

 

You are best off to get an aluminum hose end for this hose. This is often referred to as the Mickey Mouse hose because of the ears on the hose end that attach to the engine side. If you Google or Amazon "BMW hose flange" you will find any number of aftermarket parts that fit. If you get a new hose with a plastic end fitted, just carefully remove it and fit the aluminum part. This hose is very common for breaking after some number of years. If you have an N52, Rein makes a hose that has the aluminum parts already fitted. I think I got mine at Rockauto.