All vehicle engines pollute. In order to cut down on pollution, or as we say in the 21’s Century “emissions”, vehicles have a few systems to manage and minimize their effect on nature. When and engine runs it uses oil to lubricate all its moving parts, as the engine heats-up the oil gets hot and creates a gas or oil-steam. In the old old days, vehicle manufacturers would place a filter over a hole on top of the valve cover and let this gas escape into the atmosphere.
As you can imagine if one car did it no problem, but when hundreds of million cans do it, we have another form of pollution. In order to solve this problem, vehicle engineers found that they could burn this gas in the combustion of the engine while the vehicle was running. Too main issues, the gas is very dirty and you did not want to burn the actual oil. As the gas gets passed into the intake of the engine it has a bad time of making the intake valves very very dirty. Spraying fuel on the valves helps to keep them clean and more expensive fuel has better additives to keep the valves clean.
In order to keep the oil from getting sucked into the engine intake, BMW uses an oil separator system. This part of the engine is a complex mess of hoses and a specific piece called an oil separator.
In this system the oil has a chance to cool then drip back into the oil pan via the dipstick tube hose. After about 80,000 miles or 6 years it is very common for the oil separator to stop working causing a check engine light or rough idle. The hoses become very brittle and can crack or leak, this allows too much air into the air intake and the engine computer cannot regulate the fuel trim enough to control it.
These hoses are inspected at every service at Peak Auto in Apex on US-64 west next tot the Car Auto Mall. Call Peak Auto today to schedule service or a repair on your BMW.