DIY - Replacing lower radiator hose and temp sensor

[Multibeemer]

Thanks very much for this DIY. I was having trouble pulling the coolant temp sensor connector off, as I was pulling on it, rather than pushing, as was pointed out in this DIY.

[ProfessorX5]

Tried doing this today. Lower end is also baked on. Took the pan off, pried like all hell, and still couldn't get it off. Having a buddy come by and help later.

[bugbyte]

Originally Posted by ProfessorX5

Tried doing this today. Lower end is also baked on. Took the pan off, pried like all hell, and still couldn't get it off. Having a buddy come by and help later.

Try to use the heat gun or hair dryer and heat up the connector to the radiator. This will make the o-ring softer an you should remove it easily. I heated my up to about 200 degree F bottom first then top. I did all my hoses last weekend when doing valley pan, valve covers, CCV, etc. Be patient and carefully with Radiator Connector as you could break it and will cost $$ to replace with radiator.

[ProfessorX5]

Cool idea, bt carefully applied brute force won out. Now, however, I think I should have bought a new temp sensor as I might be leaking from there... are BMWs engineered to keep you from re-using old parts that are still working? :P

[StephenVA]

Now those are going to be a set of dirty nails!

[upallnight]

Originally Posted by ProfessorX5

Cool idea, bt carefully applied brute force won out. Now, however, I think I should have bought a new temp sensor as I might be leaking from there... are BMWs engineered to keep you from re-using old parts that are still working? :P

BMW are engineered to keep people from fixing their own cars. Why do you think they have coding for replacement parts?

[ProfessorX5]

LOL... ah well at least a new sensor isn't expensive.

[Doru]

Originally Posted by ProfessorX5

LOL... ah well at least a new sensor isn't expensive.

A new O-ring should actually do it. You need to know the dimensions for it. The OEM O-ring is green, and will shrink in time. There are aftermarket O-rings (black in color) made out of Viton I believe, and these will NOT leak even after years of use. The "Fanatics" have put together a post with interchangeable parts (you have to search for it - the title I believe has the words "BMW interchangeable parts" in it), and also the "Festers" have this O-ring issue documented, but again you have to search. For this one it's a thread by "Bluebee" I believe and you have to search "coolant sensor" or similar.
No need to buy a new sensor if it's working OK. Just use some 2000 grit sandpaper maybe and clean the brass element from deposits, if any.

[cn90]

- 2004 X5 2.5i with 84K miles...

- Both Upper and Lower Rad Hoses look fine, zero leaks, but I want to be proactive...

- Does anyone have any recommendation of when (years/mileage) to replace the hoses?

- If anyone has had a burst hose: when did it happen?

[80stech]

I think most of the time it is only the sensor o-ring that is leaking. Both of mine where leaking when I bought the vehicles at about 190k. Both vehicles had water pumps and thermostats replaced because they overheated before they where sold to me and neither shop noticed/fixed the leaky coolant sensor!