The PCV Valve is a little, inexpensive part that does a big job for Vacaville drivers. PCV stands for Positive Crankcase Ventilation.
The crankcase is the bottom area of the engine that holds the oil. When the BMW engine’s running, fuel is burned to generate power. Most of the exhaust from combustion goes out through the exhaust system. But some exhaust blows by the pistons and goes into the lower engine, or crankcase.
These hot gases are about seventy percent unburned fuel. 
This can dilute and contaminate the oil, leading to damaging engine oil sludge. It can also cause BMW engine corrosion, something we see occasionally at Motoring Specialists. At high speeds on Vacaville freeways, the pressure can build up to the point that gaskets and seals start to leak.
Back in the old days, engine makers simply installed a hose that vented these gases out into the atmosphere. But starting in the 1964 model year, laws mandated that these gases be recycled back into the air intake system to be mixed with fuel and burned in the BMW’s engine.
This is much better for the environment and it saves gas too. (Budget-conscious Vacaville drivers take note!) The little valve that controls all this action is the PCV valve. The PCV valve lets gases out of the engine, but won’t let anything back in. Over time, the vented gases will gum up the PCV valve and it won’t work well. That can lead to all of the problems I’ve already described, oil leaks, excessive oil consumption and wasted gas.
Fortunately, it’s very easy to test the PCV Valve at Motoring Specialists and quick and inexpensive to replace. Even so, it’s often overlooked because many Vacaville drivers don’t know about it. Check your BMW owner’s manual or ask your Motoring Specialists service advisor. If this is the first time you’ve heard of a PCV valve, you might be in line for a replacement.
There’s another aspect to the PCV system. In order for the valve to work correctly, it needs a little clean air to come in. This is done through a breather tube that gets some filtered air from the engine air filter. Now some vehicles have a small separate air filter for the breather tube called the breather element. That’ll need to be replaced at Motoring Specialists when it gets dirty.
Please ask your honest Vacaville service advisor about your PCV valve. For the price of a couple of burger combo meals in Vacaville, you can avoid some very expensive deep engine repairs.
