Most likely location (for both engine types): On top of the valve cover, near the back (firewall side) of the engine. It's a small, usually black, plastic valve with a hose attached to it.
To locate it accurately:
1. Consult your owner's manual: This is the best resource, as it will have a diagram showing the exact location for your specific engine.
2. Look at a repair manual or online diagrams: Websites like Chilton or Haynes offer repair manuals with detailed engine diagrams that show the PCV valve's location. Search for "2001 Chevy Astro PCV valve location" plus your engine size (4.3L or 2.9L).
3. Visual inspection: Once you've located the valve covers (they're the top parts of the engine), carefully look around the area for a small, capped valve with a hose leading from it. It's often near the back, but might be slightly offset depending on the engine accessories in your van.
Caution: The engine will be hot if recently run. Allow it to cool completely before working around it.
