Replace pcv valve - 2003 Ford Expedition

Here's a link on replacing your pcv valve.

Repair Guides Routine Maintenance And Tune up Pcv Valve AutoZone com Here's another link to a new pcv valve. AZ Filters PCV Valve PCV1106DL ReadReviews onAZ Filters PCV1106DL

Mike, on your Chevy PCV valve normally plugged into valve cover.
Check the attached links,instruction and guides, Good luck
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99 Tahoe PCV Valve replacment
1999 Chevy Suburban PCV Valve replacement
https://www.summitracing.com/int/search/part-type/pcv-valves/make/chevrolet/engine-size/5-7l-350

1. Pull the PCV valve from its housing and place your thumb over the PCV valve opening. You should feel it click. If the click sounds or feels mushy, replace the valve. The PCV (positive crankcase ventilation)valve is a one-way valve that recycles crankcase gases back into the engine to burn.

Yes the PCV can be replaced. It seals into a rubber grommet in the valve cover. See pitcure of valve below.

PCV VALVE LOCATED IN THE FRONT VALVE COVER.JUST PULL PCV VALVE OUT VALVE COVER. THEN YOU PULL PCV OUT OF THE END OF HOSE THEN INSTALL THE NEW ONE. FOR THE 3.8 ENGINE REMOVE THE TOP FUEL INJECTOR COVER.DISCONNECT THE ELECTRICAL CONNECTOR FROM MAP SENSOR AND UNCLIP THE MAP SENSOR FROM THE PCV VALVE ACCESS COVER AND ROTATE IT COUNTERCLOCKWISE TO REMOVE IT.TO REPLACE THE VALVE PULL THE PCV AND O RING ASSEMBLY FROM THE INTAKE MANIFOLD NOTING ITS INSTALLED POSITION AND DIRECTION. MAKE SURE WHEN YOU BUY NEW PCV VALVE TAKE OLD PCV VALVE WITH YOU SO YOU WILL GET THE RIGHT ONE.THAT WILL SAVE YOU TIME AND FUEL.

Remove PCV valve from rocker cover. Run engine at i
dle. Place thumb over open end of PCV valve to
check for vacuum. If there is no vacuum at valve, c
heck for obstruction in manifold port, hoses or PCV
valve. Repair or replace as necessary.

Turn engine off. Remove PCV valve. Shake valve and
listen for rattle of check valve inside. If a clear
rattle is not heard, replace PCV valve.

Visually inspect valve for varnish or deposits whic
h may make PCV valve operation sticky, restricted o
r
cause incomplete seating of valve. Replace if neces
sary. An engine must be sealed for the PCV system t
o
function as designed. If leakage, sludging or dilut
ion of oil is noted AND the PCV system is functioni
ng
properly, check engine for cause and repair as requ
ired to insure PCV system will continue to function
properly. An engine operating without any crankcase
ventilation can be damaged so it is important to
replace PCV valve and air cleaner breather at regul
ar intervals (at least every 30,000 miles). Check a
ll hoses
and clamps for failure or deterioration.

PCV is an acronym for positive crankcase ventilation.
The PCV Valve is a very common replacement item on many engines today. It's called the PCV valve for short but it stands for Positive Crankcase Ventilation. When your engine spins it many times collects pressure in the crankcase area, and it has to escape to relieve pressure on the motors bearings and seals. The PCV valve and PCV system is typically located near the intake manifold, and many times comes right off of the valve cover. It is very simple to replace the PCV valve, and you can do so by simply unscrewing it, and screwing in the new valve. We recommend using a little bit of teflon tape or paste to make sure you do not get any oil leaks.
Example (see picture below): 2,4 ltr. Audi V6 engine (BDV, AMM)
It's not difficult to replace PCV valve!

The PCV valve is not removable from the valve rocker arm cover. The PCV valve and rocker arm cover must be replaced as an assembly.