That is normal operation.
I believe that is caused by a plugged PCV valve or PCV hose
PCV stands for Positive Crankcase Ventilation, is a valve that releases air by turbulance created inside the engine when the crankshaft and piston are turning while engine is running.
The PCV valve will normally be located on the valve cover of most engine's. You will see a large hose connected to the valve inserted in a rubber gromet. This will be running from the valve cover to the intake box or intake manifold.
On my 2000 E150 with 4.6L engine, the PCV valve fits in a rubber grommet in the center of the valve cover, with an insulated line running to the intake manifold.
there is hose running from the top of the engine to the air intake. your pcv valve is located on the engine side of that hose. Mostly correct except there is no PCV valve; there's just a straight pipe going from the valve cover to the air plenum intake hose. Hope this helps. RJK75
There is no PCV valve on the 2.2 Liter engine.
The 2001 Mercury Sable PCV valve can be found on top of the engine. The PCV valve will be on the back side of the air cleaner housing.
The pcv valve is located on one of your valve covers.It will have a black hose running to your air breather
No PCV valve on this engine. Has "PCV system". Hose from valve cover to throttle body. Nothing to replace.
The PCV valve on a 2002 Chevy Suburban 6.0 liter engine is located in the engine. You cannot miss the valve.
Check the PCV Valve in the front half way down the engine
The PCV valve on a 3.0 Ford Taurus is on top of the engine. Valve is at the front of the engine and is easily accessible.