LJTX545I

Last night I went to replace the leaking temp sensor, and I thought I'd go ahead and do the expansion tank and lower radiator hose as well since I'm draining the radiator. It was all going smoothly and quickly until I tried to attach the low side of the lower radiator hose. Tried as hard as I could for 3 hours but it just will not slip on. Any tips on this work?

thanks,

k

e6t.lab.rat

i just replaced my leaking temp sensor also. as far as the hose, there's a metal non-removal clip that you lift to remove the hose. was this clip up when you tried to re-insert the hose? it should slide on fairly easily with this clip up, once on push clip back down. it does appear like the fit is loose but as long as the clip goes down you should be good. i too was worried about it not being on securely but no leak thus far. good luck

anrx4u

anrx4u

Interesting. I had leaking temp sensor replaced in my 05 545i this past week. Car has 40000 miles on her. The SA at the indy garage informed me that the problem is not with the sensor itself but with the O-ring that is attached to it. You can't buy this O-ring separately.

e6t.lab.rat

yeah you're absolutely right. the temp sensor rarely if at all, fails; it's the $0.10 o-ring that fails! And because this o-ring is so hard to find (trust me, i tried Lowe's, HD, specialty/indy plumbing stores etc.), BMW can only sell you the whole sensor itself.

btw, replacing this sensor is too easy. just unclip from hose, disconnect from wire and install new one in reverse. easy 1 minute job!

LJTX545I

yeah, the temp sensor is a breeze it just snaps in and out.

I had a guy with really strong hands help me he was able to get the hose on to the radiator. getting it off was strenuous also, but nothing compared to getting it back on. If he couldn't do it we were going to try some soapy water to help it.

Once the hose was attached it was just a matter of filling it through the expansion. Somehow my battery ran down overnight and I had to put it on the charger.

Replacing the expansion tank was a breeze. The hoses just slip over the new tank and snaps in place.

umermariner

Hello Guys,

Do not intend to jack this thread, however; I am sure you can help me out. I have had this car (2007 530 i with N52 Engine, Manual Transmission) for about three years now, it has about 58K miles.

Coolant is dripping from the upper side of this joint and trickling down (snapshot). If I am correct, there are three components there, lower radiator hose, plastic housing, and something inserted into the plastic housing from the top (is that temp sensor)?

Is this a common leak area? What needs to be replaced? I know replacing hoses should be really easy, however; I am concerned bcz of limited space available there (dont want to take out the radiator).

Thanks again for your help and support.

Take care.

BimmerFan52

I assume the 325i temperature sensor is the same.

DIY: How to fix a leaky temp sensor o-ring for 59 cents

umermariner

Thanks. Very helpful. I think I am going to give it a shot before anything else. However, looking at realoem, my temp sensor part number is different (its 13621433077). Unless I find the right o-ring, I may have to replace the whole.. which is not too bad (about 16 bucks on Amazon).

Thanks again.

BuddyB

Hi all,
Is the green "O" ring like the one in this video?
Skip forward to 5:30 in Video.


I went to Home Depot and picked up the package of 10 "O" rings (local BMW dealer only sells the complete sensor)
I replaced what was my shrunk green "O" ring
What a difference with the HD #31 black "O" ring, the green one did not even extend beyond the gold metal groove.

When I put the sensor back into the radiator hose it did not go in all the way because I could easily pull it up and out.
I put a very small amount of lubricant around the "O" ring like KY and the sensor went in all the way.
Clicked on the connector and all has been fine.
Make sure that the sensor locks into the radiator hose.
Another FYI, I did not know that the metal clip on the electrical connector was for pushing in on it to release the connector.
I thought that it needed to be pulled out just like the clips on the radiator hoses.

Bud