AU 5.0 vacuum investigation

[macman]

Got a few things going on with my AU 5.0 at the moment.

One issue is that when accelerating reasonably hard, the dash vents will switch from face or feet over to demist position. So searching the forums here it's quite clearly going to be a vacuum related issue.

Poking around, I followed some vacuum hoses and found a little one-way valve behind the washer bottle. Removed it, quite confident I was about to uncover the problem but it is working perfectly.

More poking around, I discovered a larger hose from the underneath the intake manifold travelling down towards the firewall. Turns out this is my PCV. Anyway, it was oily as hell and the PCV was barely connected, actually just sitting loosely on top of the large grommet it is supposed to be fitted into. I'm not convinced this is causing my problem though. Open to suggestions here.

Last thing I noticed is that there is a rubber gasket between the front edge of the lower intake manifold and the engine block. It looks like this is pushed out, or blown out (see pic). There's no leak around the area (unless it's a vacuum leak) - might expose my lack of mechanical knowledge now...

So my questions, could my demist vacuum issue be caused by the PCV not being connected? And is this dodgy looking gasket going to be causing me troubles?

[BLU-220]

if your talking about the dodgy gasket next to the cam sync ?? mine is exactly the same

cheers Dean

[macman]

Yeah, the gasket just looked like it'd been pushed or blown out. Wasn't sure as I'd never noticed it before.

I don't think the disconnected PCV valve was my heater/demister problem but I suppose it's good I found it and re-connected it.

Open to suggestions on possibly where to look for the demister vacuum thing. Stupid Max Ellerys AU workshop manual says in the diagnosis area to "refer to vacuum diagnosis section" but then doesn't say where that section is, and I can't for the life of me find it!