motopokep

i been having a coolat leak under passenger side under raditator for about a year now (2004 e60 104,000 miles)


It started last winter but went away in the summer..but now, during very cold weather (20F), it got really bad and lots of cooling is leaking on the floor under passenger side only.

I read this forum, I followed the instructions. I removed the water expansion tank and partially removed the Y- hose...well, it's a pain to disconnect the whole thing even from bottom of the car

i checked the water expansion tank for leaks..i don't think it's the problem... i filled it with tap water, plugged the outlet (where hose disconnects) with my finger, and watched it for couple of minutes for leaks.....none.

So I guess the problem is with the Y-hose



I'm guessing it's leaking only from part A. Part B is the plastic male connector between female A & C. It's a real pain in the ass to unplug the two female ends of part C, they're buried deep in there. Question, how do I remove part A from part C? There are these two metal o-rings..but they're not plug plumbing o'rings where a bolt tightens them. Do I spray some WD40 and slide them off from there?



Anyone done this? Any input would be appreciated. I had so much coolat leak that my engine started to smoke and it smelled like rubber and smell got into car salon.

I'm in my garage right now as I type this on an "exciting" saturday night. Thanks in advance.

motopokep

maybe it's not leaking at the Y-hose...maybe it's the leaking from the sensor that goes in at bottom of coolant reservoir? hmm.further investigation is due..

motopokep

leaking from sensor

Masterspy

Have you solved this problem? I was just doing some engine detailing when I noticed a small puddle on the bottom of the engine cover. further investigation shows it's a coolant leak coming from the coolant temperature sensor which is located close to where the return hose connects to the radiator. Ipulled it out and reveals the sensor with an o-ring. My sensor shows no fault so first thing tomorrow, I'll go to autozone and see if I can find the right o-ring.

Masterspy

UPDATE: Can't find the O-ring so I decided to buy the whole sensor from the dealer, cost $22 after BMWCCA discount. Problem solved.