New Air/Oil Separator box blew apart...
 

'92 745 w/ ~150k. I replaced the air/oil separator 6 months ago and drilled out the flame trap holes a little bigger. I don't really remember just how much bigger. All my leaks from high crankcase pressure went away.
Recently the fumes have been unbearable and lots of oil on the floor. I found the plastic air/oil box is blown wide open at the seam. I think I saw this happened to someone else.
Did the box fail because of high pressure from being clogged or are some of these things just junk and failed from vibration or whatever?
I'm sure it came from either FCP or eEuroparts. Should I buy a "Volvo" part? Thanks, C.

"Was it junk?" Well, apparently.
That's why I seriously advise to avoid changing parts just because "new is better than old"... Better to clean an old part, like the separator in question, than replace it with a new substandard one. Many of these replacement parts for maintenance items peddled by the suppliers are just not nearly as good s the older OEM stuff.

745 turbo? on my 92 745T, the oil seperator box is connected to a heated fitting on the side of the tube between the MAF and turbo air intake. this fitting can gum up (thats why its heated), that could block the ventilation, causing pressure pulses, which will blow out whereever they can, either blowing cam/crank/intermediate shaft seals, or the oil seperator box, or the plastic hose between the oil box and said heated fitting.

I didn't think the turbos HAD a flame trap inside the oil box.

Mine is not a turbo. The flame trap was separate and placed in-line in the larger breather line. As for the box, I still have the old one; it's in my parts tank because I never got around to cutting it open to see how bad it was. I read many posts suggesting it's just plain faster, easier and thus cheaper to replace that part. That is, unless your new part breaks. I will be checking to see if I had it under some kind of stress and I will also check the drilled out flame trap to see if it clogged?
I was posting to see if I missed something. I don't see how the system could have re-clogged after being serviced 6 months ago. Thanks, C.

huh, I thought all 1992 740 wagons were turbos, basically a stripped down version of the 940, with the 740 style seat skins.

No, not all '92 740 are turbos... There are no '92 740 turbo sedans, there is everything else in the 740 line up... And the flame trap is not inside the box, it's on top of the fitting that goes down to the separator. Both turbos and NAs use the same separator.
The NAs have flame traps, turbos don't, and I don't see why expanding the holes of the trap would be a problem--not that it is needed. They all have oil separators.
Who knows why it blew apart? Bad seem job?

Clean the old one, put it back in. I root it out the best I can with a hooked home made wire hanger type device, then flush it out with solvent. Works every time. I never buy new ones.

Same thing happened to me, 3 months then the seam opened up, wished I didn't throw the oem part away! I tried using some ABS cement on the seam which worked for a short time, now I'm ordering a new oem part from the dealer. $59.00 all of the related plumbing was cleaned when the new part was installed including the draintube that was kinked and not allowing the oil to drain back to the pan quick enough, the oem part leaked from the o-ring on the bottom when I replaced it. my car does have turbo.