Moisture accumulating in the engine oil separator; hose to oil dipstick guide tube; or the orifice in the dipstick guide tube can freeze. When this occurs, depending on the position of the internal valve, it may either cause high crankcase pressures (stuck closed) resulting in valve cover leakage and/or breakage, or cause an oil hydro-lock condition (stuck open), with smoke from the exhaust pipe,rough running and which could result in engine damage.
 |
| #1 Normal Breather#2 Cold Climate Version |
BMW and Northeast Motor Werks Recommend installing the cold climate version of the crankcase breather and associated hoses,along with the latest modified dipstick tube.This modified valve and hoses has foam insulation encapsulating the valve and hoses,and the dipstick tube has a larger drain orifice so that there is less of a chance for any condensation to build up and freeze.
With all that being said, we have still seen the insulated valve fail on high mileage engines due to the fact that the rubber diaphragm inside the valve has deteriorated and split.
