540i

Quick update in case anyone ends up having the same issue. I ordered a new thermostat for $40 on ebay and replaced it myself. Everything has been working perfectly. So a savings of around $1250. I wasn't surprised the shop was trying to screw me over. I've been keeping an eye on the coolant and oil temperatures with the android "Torque" application and everything is working just as it should.

Gilgorm

Glad you got it fixed. A non-operational thermostat is like plugging one section of the system loop.

BimmerFan52

Congratulations!
It is satisfying to self-diagnose and save the dough.
Did you also replace the coolant reservoir tank (missing stick)?

540i

No I didn't (yet.) I wanted to make sure that the thermostat was the issue before touching anything else. Reading some other threads I'm sure that the tank will need to be replaced soon as well since the stick is missing.

540i

Ok, so I found another small leak coming from the upper radiator hose. At first i thought it was the hose but when I took it off, i saw that the plastic piece that the hose goes around is cracked and just broke off. I caught it before it could go anywhere.

After doing more research, I'm confused. My hose does not look like part number 17127519248 in this link (02)

RealOEM.com * BMW E60 545i Cooling System Water Hoses

BMW Radiator Hose - From Water Pump 17127519248 - RM European Auto Parts

My hose look more like this one.

http://i.tfcdn.com/img2/1jJJ_z8AY5r8...OAA**/fyVMtP8A

Basically it only has two ends - one clips into the plastic piece on one side and the other into the radiator on the other side. Does anyone know if they sell only the plastic piece (clamp?) on the left side of the image that the actual hose goes into or what that piece is called? I am having a hard time finding the complete hose that I actually have...

BimmerFan52

Double check your hose. At first glance my hose appears as though it is only one single hose. If you run your hands underneath the hose plastic ends however you may discover the secondary hoses coming off the plastic ends (sort of hidden by the larger main hose). I have not seen these plastic ends available separately and don't know how you would attache them to the rubber part of the hose in any case.

Our 545is are hitting an age where engine compartment heat seems to have brought the coolant system plastic components to the end of their useful life. Replace all of the hoses that have not been replaced recently in addition to your coolant reservoir so you can sleep like a baby.

540i

I double checked the hose (i took it off when I was replacing the thermostat) and there are no secondary hoses. Thanks for the advice, I'll keep looking for the correct hose.

BimmerFan52

Is your transmission auto or manual?

540i

It's auto. Per the link i posted earlier they both have at least one secondary hose...mine doesn't have any.

BimmerFan52

Yeah, your auto should have two. Any open holes where the two hoses normally connect?