does that mean it doesnt work?, how can i tell if the egr valve works still?
The EGR valve needs to be closed at idle. There should be suction in the hose, opening the valve only at cruise speed. On SOME EGR valves, you can stick your finger in the diaphragm and open it manually. The engine will sputter when you do this. I saw a tester do that at a smog check place. Otherwise, they have to use a little device that hooks up to the valve and sucks on it to test it.
You didn't tell us year, make, model, and engine so we're shooting in the dark a bit. First off, EGR valves are NEVER on at idle. That would kill the engine. The vacuum only comes on when certain conditions are met. First, the engine has to be at full operating temp. Then, the throttle has to be open a certain amount. If you own a late model vehicle, many of them used duty cycle solenoids that literally pulse the length of time the vacuum solenoid allows vacuum to go to the EGR. That's how the computer regulates how far the valve opens. So, the only way to tell if yours is working without owning a scope is to use a hand vacuum pump and attach it to the vacuum port. Then apply vacuum and release it while watching the valve open and close. If you do this while the engine is running, the opening valve should make the engine run really rough, if not die completely. Next time please give us more make/model info
Not sure how to answer. First the vacuum line going to your egr only has vacuum under certain conditions and never at idle. If you have an egr code/problem.... email me with code/syptom and vehicle info i'll try to help further. :)
