What's a vent box?

[shawn_75]

So SWMBO took out 01 XC to the dealer today. We were having some idle issues for a few weeks which turned into a driveability issue over the past few days. The check engine light set in on Sunday, finally. The idle issue wasn't too bad, it only stalled on us once. When it started surging badly, it tried to push you thru things like stop signs, garage walls, cars sitting in front of you. etc... Eventually, we started shifting into neutral when we'd approach any type of stop. We also had a funny chattering solenoid that chattered really fast, like 10Hz fast. It carried on like this when the car was shut off for a short period of time, and sometimes I heard it while it was running. This solenoid, which is aparrently the turbo boost control valve, is clipped onto the air filter box just below the mass airflow sensor.

Dealer did the following, 30677021-5 ECM GASOLINE UP and 9473212-0 SOLENOID VALVE.

The notes on the bill show the code CEM-1A62.COMMUNICATION WITH ECM FAULT, ECM UPGRADE and replacement of TURBO BOOST CONTROL VALVE. It also goes on to say WILL NEED VENT BOX REPLACED IN NEAR FUTURE.

So what's a vent box? It is aparrently around a $400 job to replace this and they indicated that it had alot of crud in it. :confused:

BTW, the car doesn't surge and buck anymore but the wife and I both agree that it doesn't feel the same as it did before all of this started. A little less peppy and less sure of itself feels like a good description.

Shawn

[JRL]

I would assume they mean the breather box, this is your PCV system.
If it get clogged up the oil will go other places... like out your rear main seal!
Clean or replace it. The part is cheap (30-40 bucks) but it's a 4 hour job

[shawn_75]

That sounds about right given the labor rate. I imagine that I can do this myself. This won't require and software updates, I assume? Where is it located?

BTW, I have a used bevel gear sitting in my garage that I replaced and will be posting some pictures soon for those that may be interested. I can say that the vent is not accessible without removal of the gear.

Shawn

[Willy]

Perhaps this can help:
http://www.volvoxc.com/forums/showthread.php?t=9722&highlight=pcv
Willy

[shawn_75]

Thanks Willy,

But this does not reference a vent box at all. Or am I missing something?

Shawn

[Art]

Actually, Willy is not too far off the mark. I believe that the vent box is also referred to as the breather box or oil trap and is located below the intake manifold. (See part #1 in diagram below).

http://www.fcpgroton.com/images/oiltrapv7099.jpg

From the VCBC:


The crankcase ventilation system consists of a breather box (a hand-sized molded black plastic housing lurking under the intake manifold), a flame trap and a number of hoses. The breather box is responsible for allowing fumes from the crankcase to escape without having oil escape with it. If the breather box, flame trap or supporting hoses get plugged, the crankcase pressure will build up and will cause most if not all of the various oil seals to leak. In extreme cases, the seals may be damaged, requiring replacement. The flame trap and the hoses associated with it should be inspected to see if they are trapped with carbon. If the hoses are brittle they are getting plugged with carbon and should be replaced.
The flame trap sits on top of the breather box. The breather box cannot be successfully cleaned; it is simply replaced. The exact service interval depends on many factors.