Inside Anatomy of a Volvo Oil Trap

[cn90]

For reference thread....DIY: 1998 Volvo S70 GLT PCV Mod: no more smoking dipstick!
https://www.matthewsvolvosite.com/forums ... =1&t=53448

Ever wonder what is inside the Volvo Oil Trap? I had some time today so I sawed it off.
Well, it is simply a plastic box, sort of...

Note that:
- From Top Engine ---> Port with O.D. = 11/16"
- Vent Port O.D. = 5/8"
So they are slightly different in size (difference = 1/16").

VolvoOilTrap.JPG (69.38 KiB) Viewed 5158 times

[abscate]

Nice write-up and demystification of the PCV system

[jacobharding]

Thanks for that. I am soon to be replacing mine this spring and it helps to better understand how it functions. My dipstick smokes a little and I have noticed more oil seepage since switching over to synthetic oil. I would appreciate an experienced opinion on a quality replacement. I will also be doing a timing belt, tensioner, and probably water pump too just for ease of mind. Is there anything else I should consider replacing while I have the engine bay opened up to that extent?

[cn90]

1. PCV Job ---> See the link in the very 1st post above. Note that I used 5/8" hose to vent ---> no more smoking dipstick.
- The Oil trap I showed above has 150K miles, does not look too bad.
- In theory, you can re-use it if you are tight on budget, if not, replace it.


2. Timing Belt, WP etc. I wrote a very detailed DIY here, just take your time to go over it.

DIY: 1998 Volvo S70 Timing Belt Overhaul, Water Pump, Cam Seals, Serpentine Belt Overhaul:
https://www.matthewsvolvosite.com/forums ... hp?t=53722

[jacobharding]

Excellent, thanks! I have a oil trap in my parts bin from a 190k engine. I wonder if I fill it with something like seafoam until I get around to the repair if it will break up all the junk inside. The trap otherwise appears to be fine.
One question I have about your post is how the 5/8 upgrade could help if the opening in the oil trap is still 3/8. Or is the opening larger and it has a fitting to step up the 3/8 line?

[erikv11]

... I have a oil trap in my parts bin from a 190k engine. I wonder if I fill it with something like seafoam until I get around to the repair if it will break up all the junk inside. The trap otherwise appears to be fine. ...

Absolutely

As has been posted many times, for the oil trap it is almost always fine to just clean it out and re-use it. Or buy aftermarket - no reason to spend a lot of $ on a hollow plastic box.

https://www.matthewsvolvosite.com/forums ... =1&t=46227
https://www.matthewsvolvosite.com/forums ... =1&t=21250
https://www.matthewsvolvosite.com/forums ... =1&t=38243
https://www.matthewsvolvosite.com/forums ... =1&t=38111
https://www.matthewsvolvosite.com/forums ... hp?t=53448 (read the comments that follow the write-up)

etc.

[cn90]

1+,

My advice is: soak the oil trap in gasoline for about 2-3h.
Do this outside your house.
The use a long screwdriver to scrape the inside a bit, especially at the openings.
Then rinse with water so all the gunks come out.