check valve question

[tigmaned]

what are signs the check valves that are on my 86 vette factory emission exhaust are bad??
i am asking since after my vette has sat a day or more at start ups it seems like the exhaust system under the hood is building up and then it get quiet? are they all like this or is something not working right? i know there alot of stuff to this system, smog pump, air verter, check valves on boths side just to name some of it.

 

[86PACER]

The way to check the PCV Valve (on valve cover), is to pull it out of the grommet and place your finger on the bottom of it when you have the motor running. It should apply vaccum to your finger. Also when you shake it, you should hear the internal valve rattle around meaning it is not stuck.

 

[G Winter]

I think 68 pacer is refering to the check valves on the air pump system. Often it isn't the checkvalves. The pump may be making noise or there could be an air pipe burned through. The valves are quite simple, most are spring loaded,the pump overcomes the spring to open the valve to supply air to the exhaust. There is also another control valve but I don't remember if it is electric or vacumm controled.

Glenn