How to change Engine coolant temperature sensor?

I have been looking for the DIY to change to ECT but not the one coolant temp sensor in the lower radiator hose because i already changed it and my mechanic told me that i need to change the oil/water temp sensor in the driver's side of the head near cyl #6.

it is for 2002 bmw 325i

I researched a lot but couldn't find it yet.

part #3:


This is the part i need to change i guess:
http://www.oreillyauto.com/site/c/de...1392&ppt=C0039

I seen that engine temp sensor while doing CVV change. I do not think it is doable from the bottom. Probably need to pull all intake hoses, and throttle body at a minimum. If your CVV has never been done then pull / change it and all associated hoses which will also gain you access to that sensor.

Curious, you never mentioned what symptoms this failed sensor is giving you? Fault codes? Cannot find it in Bentley's other than in the schematic and how it feeds info to ECM.

check this link out for more info/help: http://forums.bimmerforums.com/forum....php?t=1558742

my problem has a long story. i went to dealer and got diagnostics and they told me i need to change lots of stuff on cooling system. I changed but they didnt mention anything about sensor.
i changed the sensor on lower radiator hose and leak stopped but,

my problem on the car is when i start the car the temp needle goes all the way to red and and then back to blue and after 5 min driving it becomes normal, and sometimes car cranks but doesnt start and after 4-5 times trying it starts with a gas smelling.

yesterday i went to mechanic and gave me this diagnosis with explanation of i need to change that part on the first picture:

According to diagnosis:

010 OA engine coolant temp sensor not present 255 times (shorted to or open)

245 F5 Secondary air 47 times
246 F6 secondary ait 47 times
222 DE 02 sensors not active 9 times
008 08 air mass flow sensor not present 2 times (shorted or open circuit)

Interesting....thanks for the info. Yeah, I can see that....011 is engine coolant temp sensor (outlet- the one on the hose) 010 is coolant temp sensor....
I would change that sensor too (#3) and consider CVV why you are down there....unless it has been done in the last 60k. Indy must feel this shorted sensor is sending erroneous info to ECM causing all other issues. Does sound like the place to start....unless you get really lucky and it is just a loose connection? bumped during recent maintenance?...you may be able to pull lower intake boot and get your hands on it.

i wonder how much dealer would charge to fix this?
i called them but no one is answering!