purge valve?

[jaip]

anyone have a diagram of the correct pipe connection for this? its the valve that is attached to the radiator/fan casing. should the metal pipe vent to air?

[jaip]

it also clicks, should it?

[jaip]

[Antherzoll]

Yes it should click. No it should not vent to atmosphere.

Should connect to the vacuum circuit that is connected to the barb on the top of the manifold. The circuit draws vacuum from the intake manifold and the air intake pipe and has a 2 check valves. One check valve to prevent the flow of air from the intake pipe into the EVAP circuit when the intake manifold has greater vacuum, and one check valve to prevent flow of air from the intake manifold into the EVAP circuit when the intake system is in boost (intake manifold pressurized) .



Part #21 in this image

http://www.tascaparts.com/oe-volvo/30757307

Here's a pic I edited. Big red arrow point to the intake connection. Within the green circle the arrow points to the tee connection, the bottom of the tee goes to the purge valve, the left goes to the intake manifold barb w/check valve closed to manifold, the upper goes to the fresh air pipe w/check valve closed to intake pipe.

[Antherzoll]

Took a second look at the photo and it almost looks like a BCS was installed instead of a Purge Valve.

BCS


Purge Valve


You can see that the purge valve has 2 ports where the BCS has 3.

How does this affect the circuit, well it shouldn't. Referencing this image:


The BCS and Purge Valve operate similarly. When either valve is "ON" it will close the circuit between blue and yellow allowing air to flow between those ports. The difference being that when the valves are "OFF", the Purge Valve will open the circuit stopping air flow where the BCS would open the circuit between blue and yellow and close the circuit between yellow and red allowing air to flow from yellow to red.

All you'll need to do is securely block off the open port and it's effectively a Purge Valve.

[jaip]

That's Amazing, thank you. And you are correct that the item fitted seems to be a Tcv valve. I'll block the vented end up until I can get hold of a new one. Thanks you again for your help, time and advice 👍🏼

[volvoxc90bob]

I replaced my hoses on the Evap system and I'm not sure if I have the two check valves pointing in the right direction, the check valves have arrows on them indicating direction of airflow. Right now I have the fresh air pipe check valve pointing away from the fresh air pipe so it is sucking in fresh air and I have the other one that goes to the intake pointing towards the intake allowing air into the intake. Reading the above thread I'm thinking both of these check valve arrows should be pointing in the same direction allowing air to vent into the fresh air intake and allowing air to vent into the intake manifold. Can anyone confirm the direction of airflow for my 2004 xc90?

[Voldog]

I realize this is an old thread but I researched the P0497 code I got yesterday on the CEL. All the hits on google pointed to the Evap Vapor Canister Purge Valve. I was ready to order it from FCP. But I closely checked that area on my car and noticed that the vacuum line going to the intake manifold (RED) was had gashes. The picture attached shows the area and that line already removed (note the barb connection in GREEN)). I also noticed that the lines pointed in LIME GREEN where degrading (getting powdery). I decided to replace those lines including the line going to the intake manifold up to the check valve.

I ran the car again and the CEL cleared.

[Astro14]

I replaced all of those lines a few years back, when I did the PCV system.

While they're not related, it was a lot easier to do when the manifold, intake piping, etc. were out. So many vacuum lines crumble with age and cause problems, that when the car gets to 10-15 years old, it's time to just carefully do them all.

Buy line in bulk, get good quality line in a variety of sizes, and go through the engine bay. Save yourself the trouble with a few hours of PM.

Same with wire loom. Spend a few hours when you've got the manifold out, and replace all the crumbling wire loom.

[Voldog]

Thanks for the response. I have no reason to open up the manifold right now but I will keep your suggestion in mind. Btw, where do you buy the tubing in bulk?