Fyi

I had a small leak at the front of my 6er passenger side. Could not figure out what it was until recently. Turned out to be a leaky temp sensor in the radiator hose coupling..
I thought it was the hose at first and replaced it today. Very easy by the way. Took three hours but only because this was my first hands on engine repair on a BMW and while on the lift got acquainted with the underside. If I had it to do again it would only take about an hour. I put the old temp sensor in the new hose and it started leaking right away. Got a new one from BMW, put it in (5 minutes) and shes back to no drooling anymore...
Hose, Temp sensor, 1 jug BMW anti freeze about 100 duckets... Knock on wood I got off really cheap for having something go wrong on my car....

PS never use anything other then BMW antifreeze I found out. The stuff has come a long way. PH balanced, no phosphates and probably much more. It doesn't look like regular anti-freeze either. But it wont harm any seals or rubber gaskets, cause rust ect...

Hope this might help some of you out...

I had the same exact thing happen. I bought from the dealer the lower hose and a gallon of antifreeze, got home to replace, popped the sensor in the hose and it was still leaking with the new hose. turned out to be the green o ring on the temp sensor, took no time to fix. i put the old lower hose back on and returned the new hose and got my money back. no leaks.

I have pictures in my post, on the second page right now labeled coolant leak. at first i went through the bottom of the car but so much easier from the top. cheers

I left the new hose on, didn't want to temp Murphy any more then I had to. But the parts guy at BMW said the same thing it always the rubber O-ring on the temp sensor.
Also for those reading that might come across this, be very careful as the radiator is made of plastic and you can damage the fitting the hoses connect to if your too aggressive.
My hoses came off and went on easily...

True. you break that and you break your wallet. my hose came off fairly easy but it took some wiggling and a little finesse.

Originally Posted by Superhart1977

I had the same exact thing happen. I bought from the dealer the lower hose and a gallon of antifreeze, got home to replace, popped the sensor in the hose and it was still leaking with the new hose. turned out to be the green o ring on the temp sensor, took no time to fix. i put the old lower hose back on and returned the new hose and got my money back. no leaks.

I have pictures in my post, on the second page right now labeled coolant leak. at first i went through the bottom of the car but so much easier from the top. cheers

I'm about to install my old hose back on and return the new one as well

Thanks for sharing coug60. Experience is the best teacher