PCV / oil crud

[speedy25]

Starting this as a new thread for finding a better solution rather than clogging up the intake cleaning thread.

Originally Posted by kickfli12

i thought the same thing until i put a catch can in line of the pcv system. after about 6000k (2 oil changes) i dumped about 1/4 of a quart of oil out of it. for me thats 2 gallons of oil that has passed through it in its current time on the road (my car has 192k). since the oil is traveling so slowly it has time to attach itself to things and gum up. well this is at least MY experience with these pcv systems. this is my 3rd 1.6L corolla and my previous 2 were full of oil as well. to ME this makes sense lol

NOW, if the pcv system was working properly, the actual flow of gases or liquid would be very small. A light vacuum would hold everything inside the crankcase as the pistons go up and down. Of course we know that isnt reality. Typically as the rings wear, blowby causes the PCV sytem to work harder. Some older/abused engines with severe blowby totally overwhelm the system and all the crankcase fumes and whatever else mixed in it gets sucked into the intake, and of course you have followed one of those cars at one time through the blue cloud.

Some cars I have worked on didnt seem to have a very good separating system, with little or no filtering. Some had a lot, but with high mileage those filters got clogged and failed.

I think its time for an experiment. I'll add a catch can like kickfli talked about and take it a little bit further. A pressure gauge to actually monitor crankcase pressure. (which should be next to nothing) and I'll do all this AFTER I do another leakdown test to confirm ring sealing.

Anyone else who cares to do the same it would be as interesting or even more than the chatter about fuel mileage.

My car consumes way more oil than it should. The outside of the engine should be close to dry now that I resealed the oil pan. But 1 qt for 600 miles is way too much for the leakdown numbers I had when I bought the car. Yeah, I need to do valve seals too, but that shouldnt account for the high oil consumption.

-SP

[kickfli12]

that sounds like a great idea. i was amazed at how much oil i dumped out of that thing.

[Piloter]

Originally Posted by speedy25

1 qt for 600 miles is way too much

You got that right, but that's about my consumption rate too and has been stable for the past, well, let's call it 160K. Last time I got a compression and leakdown test done (about 80K ago) the numbers were all in the 180s and the only leakage was through the rings and seals.

My inline catchcan picks up a pretty good amount of blowby, and I do leave a bit of a trail. Engine braking especially is good for discouraging persistant tailgaters...foot off the gas on a long hill, and I can make cars behind me almost VANISH when the pedal goes down again.

I've tried everything chemical that's supposed to dislodge stuck rings and recondition seals, even down to piston soaking, but I am convinced the problem is sheerly mechanical at this point. The good news is that the condition doesn't seem to be worsening.