[hawkjr1]

I have a 2013 BMW 535i with the N55 engine. My car is losing anti freeze somewhere. I am guessing about 5-6 oz. a week. Never saw anything on the garage floor. I also pulled the underpin cover off of the car and there were no signs of antifreeze.

The only place that was wet is the where the orange/black hose connects to the intercooler on the passenger side bottom. I checked the thermostat and it was good and the water pump and all of the other hoses show no sign of a leak.

My question is do that hose supply (orange) antifreeze to the turbo. I have little knowledge about how the turbo operate. I took that orange hose off and it is in good working order and no antifreeze in it. I change the oil and saw no sigh of water in the oil (head gasket). Can someone clue me into what might be the problem?

[mcdanielvzw]

Not sure if this will help you, I just had to replace the venting hose on our N55 X1 because it was leaking at the connection to the expansion tank. That was hard to track down, but the inner O-Ring was flattened due to time/pressure.

I replaced the expansion tank first since diagnosing looked like the top/bottom were no longer sealed, did the bleed procedure, and saw fluid dripping from that joint.

Of course don't do what I did and break the plastic nipple on the main hose from the engine to the radiator when you replace it - It is fragile, and ours was an additional $80 for that hose same day at the Dealer.