Hi!

I replaced the PCV system (flame trap and oil box) and associated hoses, but my car continues to fail the glove test. I was thinking: could I just drill a hole in the oil cap to relieve excess pressure? Maybe have it route to a catch can? Alternatively, could I take maybe the breather hose off the flame trap and route it to a catch can?

I don’t have the energy to take the whole intake manifold off again, nor do I want to check every single vacuum hose. Just thought this might help alleviate pressure - especially since my front cam seals are blown and I’d like to get rid of excess pressure before replacing them. I don’t have to worry about an inspection from the local authorities. So, that’s not a problem.

Any thoughts?

why not do a full flush,,drive around at an even,30-30 mph speed for about 30 miles w about 1/2 a bottle of oil flush,,& totally dissolve what ever is clogging it up..Then drain the oil & filter & replace w a good synthetic,,track down all the vac hoses will save you $$$,,on my 940 the intake manifold gasket is pretty simple,,I no sure what engine you have but read the directions a few times..I like to lay down & visualize it & it doesnt seem so daunting

You could do like some older cars have - run a vent line from the cap to the intake tubing behind the mass air sensor. Older cars returned the vapors to the air filter, but this might bugger up your mass air sensor.

That way, your engine could burn the oil.

You could also add an old fashioned pcv valve - they were a short, wide tube with a ball inside to act to regulate the flow of pressure. any auto store should have one.

I found several articles about pcv valves and catch cans on google, including a valve that is adjustable.

That’s exactly what I want to do: the PCV valve itself.

What's wrong with spending 30 minutes examining the engine vacuum lines and elbows? It will take much longer to install a catch can.
--
Keeping it running is better than buying new

How many miles? Blow-by can get to the point that the OEM systems simply can't keep up with the volume/pressure in the crankcase that results. Trying to solve a "problem" like that by creating even more ventilation (hole in the oil cap) is akin to taking a Tylenol for a headache.....that's caused by a brain tumor. You may get some short term relief. But bigger problems loom.

So, the question is -- is the excess crankcase pressure the problem, or merely a symptom of another, larger problem?
--
82 242-6.2L; '17 Mazda3; '16 Crosstrek

The car has 132,xxx on the clock. I am sure it’s just old age causing all this. The car runs great otherwise.

The big thing is that I don’t want to do the cam seals only to have to do them again in like a month. The car leaks a lot of oil from those blown seals and it’s ruining my driveway. I figure alleviating the pressure via a Tylenol-style fix might buy me some time.

130,000 is getting close to a common failure time - head gaskets.

My redblock eventually had its head gasket fail and combustion gases blew by the gasket and into the crankcase, causing excessive crank pressure.

It's time for a compression test.

Head gasket failure on the white block engines is almost unheard of. In either the 6 cylinder or 5 cylinder engines. They are an all-aluminum block and head so there is no temperature disparity between the block and the head unlike on the red blocks.

Excessive sludge buildup is the usual cause for leaking seals. A very good reason for running synthetic oil exclusively in those engines...:)

--
Will I buy another Volvo??? We'll see....

If it were my car, I’d throw away the flame trap screen at a minimum. Did that on my 240 and 850 with no issues. You could also throw away the entire flame trap and replace with a hose as you more or less mentioned.

If you are willing to go down this road, you could also try Auto-Rx. Might help. An excellent sludge cleaner. Used it on my 850.

Out of curiosity - Did you ending up replacing the rear cam seal? Was it the cam positioning sensor that was in the way?

--
Will I buy another Volvo??? We'll see....

Rear cam seal isn’t leaking. I’ve visibly confirmed the leaking front seals.

I’ve actually eliminated the plastic bit in the flame trap, but I’m still getting all that pressure to inflate a glove. I did some reading and I thought about doing what another did which is just do a T connection off the flame trap hose and have a vent there. I might just try what you suggested first and eliminate that flame trap holder.

Last resort I’ll try Auto-Rx. I’ve heard that stuff can soften seals to the point where the leak even more. I’d rather not start a new leak haha