Flame Trap / PCV service in my 240

[eebird]

I know the flame trap has been discussed a bunch, but just wondering...how would I know how often this needs to be serviced/cleaned in my 1992 240? I have had it serviced once by a Volvo shop in my 8 years of ownership, but is this something I ought to have done yearly or every couple years? I don't put a ton of miles on this car, but I do drive it. Maybe 1500 miles a year.

Are the flame trap and PCV system just different words for the same exact thing? Or are they just related/part of the same components?

 

[smeha]

PCV - Positive crankshaft ventilation, also a flame trap.
PCV oil return hose in the block, breather box, rubber Z hose, plastic T connection with plastic filter insert, small short vacuum hose from T to manifold, and breather hose from T to air intake boot.

I do it every 2 years with OEM hoses and OEM breather box(i had couple times aftermarket one in, but I heard they do split in half sometimes), comes down to $100.
Great addition in preparations for California smog check.

I also shove long hose about 3/4 inches into PCV return hose in the engine block and blow in it with no extra pressure to see if it needs cleaning/replacing.
If you do decide to replace PCV return hose, 99% you will need to remove engine pan and suggest cutting new hose short for future easy serviceability.

 

[Khrrck]

Flame trap is a little plastic or brass insert inside the plastic holder in the middle of the PCV system. Has a bunch of small holes which let air/oil through but get in the way of fire, so theoretically your oil pan doesn't explode. Unfortunately the small holes also clog with sludge easily.

I got the relocation kit from IPD so mine is up above the intake manifold level and I can easily just pop the top hose off, inspect, and remove for cleaning as needed (It's not needed any cleaning yet). Everything else in the PCV system has relatively large holes and doesn't clog nearly as easily. Definitely worth checking the breather box every few years but I don't see a need to replace it, unless it's clogged and solvent or mechanical cleaning doesn't work.

 

[dl242gt]

I would service the flame trap part of the pcv system by cleaning or replacing worn out parts every year for a daily driver. The hose between the flame trap holder and the separator box likes to crack and cause a vacuum leak. As does the little vacuum hose which will also clog.

For a car only driven part time such as your every couple of years I'd take it apart for cleaning or replacement of hoses/flame trap.

 

[dl242gt]

The separator box service is more of a long term maintenance task. I'd say about every 100k miles for service or replacement. Unless it's an urban stop and go car all the time. Then I'd service it sooner.

 

[eebird]

As mine is a 1992...am I correct that on my engine the flame trap was already relocated by Volvo to a more easily accessible location?

 

[hessam69]

If you change the oil every six months, it won't have a chance to block the oil trap again but do clean the flame trap every couple of years

 

[Khrrck]

As mine is a 1992...am I correct that on my engine the flame trap was already relocated by Volvo to a more easily accessible location?

Should be, yeah. Follow the big hose off the "accordion" intake hose to a spot on the firewall side of the intake manifold.

 

[dl242gt]

'Easier' is a relative term. It's still stuffed down between runners three and four of the intake manifold. The kit from ipd raises that up a bit more so it's even more accessible.

 

[84B23F]

'Easier' is a relative term. The kit from ipd...

Pic of my setup; left over drain hose for a Mini-Split [Mini Split 15' Length 5/8" ID PVC Braided Drain Tubing]

Caution - If removing existing hose, I would place one hand on top of Oil Separator Box while removing existing hose. Otherwise, the top of oil separator box might break open.

 

[dl242gt]

Yes, much better.