Hi there.

Still chasing down my lumpy idle issue, and have a question about the EGR valve which I have removed from the car.

If there is no vacuum applied to the diaphragm (ie EGR valve closed), the manual says there should be no airflow between the two large ports which connect to the plenum.

But after cleaning the valve with carby cleaner, if I blow or suck on one side which connects to the plenum, there is still airflow to/from the other side.

Is it normal for this to occur when doing this test by mouth, or should there be ZERO air movement with the valve "off"?

Do I have to try cleaning it again or is the plunger/seat stuffed and a new valve required?

It's definitely not much flow if I suck or blow on the EGR really hard, but it's definitely not completely sealed.

Anyone?

Can u block it temporarily to see if that fixes idle issue?

Yes, I guess that's the next possibility if no-one knows if a small amount of air movement when it's closed is normal. Luckily I had a coke can for lunch.

Is the diaphragm holding vacuum OK - other wise air will go back into manifold from there, as opposed to just adding extra exhaust into the manifold at idle if it is a valve seat issue??


Have a look at


http://www.youtube.com/watch?v=PvN2olCzfws

Yeah the diaphragm side is holding vacuum fine.

I don't know about air, but when I cleaned mine the valve was able to hold carby cleaner without leaking through, and that's pretty thin, so I would think yours might be stuffed. If you are concerned, one way of blocking the EGR (temporarily for the purposes of fault finding, I won't recommend blocking it permanently) is to cut a blank from a Coke can and fit it in place of the gasket at the top of the gas riser pipe, effectively blocking the system. If no difference, EGR ain't the issue.