quick question on PCV system...

[caryhorner]

Is the "oil trap separator" the same thing as the "breather box"? I see mention online of said breather box for pre 99+ volvos but not for mine (MY02 V70XC). I'm wanting to inspect this for clogs...

[JRL]

That's just one part of the breather system

[caryhorner]

breather "system"... meaning the PCV system? I guess what I'm wondering is... when someone says breather "box", is there an actual box or are they referring to the system as a whole?

[Scopeman]

It is an actual box, located below the intake manifold on the block. With a flashlight you can see parts of it if you look enough.

[JRL]

The box is just one of the parts.
That's nothing, 20 bucks, and can usually be cleaned but the rest of the parts, all the hoses and nipples are what clog up.
To replace the box itself costs as much as replacing everything, it's buried inside the motor and the intake manifold must be removed

People says "breather box" as common vernacular but mean replace the entire system.

[Reverend]

Is the "oil trap separator" the same thing as the "breather box"?

Yes, it is.

However, the best way to check the PCV system is to use the rubber glove test - hold the glove tight over the oil filler and it should slightly suck in from the vacuum. If it inflates you have pressure in the crankcase and need the PCV service. You can also do that over the dipstick hole.

The PCV service is more parts to replace than just the oil separator box. You need the hoses and little rubber parts, etc. FCP and IPD both sell a kit. First time doing it for me took two half-days and some swearing.
There's a tweak using some XC90 parts and not spending the money on the $180 hose in the kit. You'd have to search a bit to find more on that.

[Scopeman]

And, the "rubber glove test" at idle is not completely definitive. There may be crankcase vacuum at idle, and not at high speed or under boost. The breather system has two circuits; one for idle, and one for cruise. Either or both can be partially or completely plugged. My 2005 at 80K miles, had vacuum at idle, but pressure at cruise. There is a YouTube video made by a Volvo tech demonstrating this. The relay solution is to replace ALL the parts. I used the IPD kit, completed it in about a day.