mustangmarty
Veteran Member
How do I test a pvc valve from a 1z motor to see if it is bad?
Ok, the inside is very sooty, oily, dirty inside all three ports. When I do that test, I can hear the diaphragm pulling down. When I release the intake ports, there is barely a slight restriction of air flow which becomes unrestricted airflow after only a half a second. My vacuum source was just me sucking on the outlet port though. Will soaking it in soapy water help things?Yes, the valve can be tested.. Remove it from the valve cover and close off both inlet ports with your fingers. Now apply vacuum to the outlet port. You should be able to hear and feel the diaphragm being pulled down. While maintaining vacuum, remove both fingers from the inlet ports. The vacuum should hold. If the valve's interior is particularly dirty, it may only hold vacuum for a few seconds, but it should hold at least briefly.
Actually, it won't prevent the start of a runaway when upside down, although it will partly restrict the amount of oil consumed once the runaway is really cranking.Why are you worried about it functioning? It's not there to keep blowby oil out of the intake. It never closes in normal operation.
What I've read is that it's to keep the engine from running on oil if you turn the car over.