And another turn for the wierd

[98ACR]

This morning I couldn't sleep, so I decided to go for a drive.

I took some rarely traveled back roads, picked up highway 78 for a good WOT blitz, and back around on some well-traveled surface streets. Shortly after getting off the highway, I smelled the acrid stink of burning oil. Since I was the only car on the road, I knew I was the source of the smell. I quickly pulled over, cut the engine, and popped the hood. About 1/2 cup of oil had spewed out of the dipstick tube all over the engine. I figure this was partially because I have the secondary crankcase vent capped off (this is the one that is directly over the distributor and is plumbed into the intake tube) I capped this off several weeks ago in an attempt to reduce the carbon build-up in the intake. But I also guess that the PCV had a temporary failure preventing ANY crankcase pressure from being vented. I replaced the PCV with a fresh piece and put one of those cheap breathers on the secondary vent and I'll be monitering it to make sure this dosen't happen again. This car just keeps getting wierder...

[6G72Galant]

:?

[DOHCstunr]

Nothing weird about it.


yeah you don't want to cap off your breather line,
now you have been driving with no way to ventilate the crankcase pressure.
how is the pcv supposed to relieve pressure from the crankcase if its source for air is sealed off,
answer... it can't
i'm suprised your dipstick didn't pop out earlier. suprised your pcv valve didn't pop out either.

best part is that build up of extra pressure actually causes worse blowby conditions, due to poor sealing of the rings.
increasing crankcase vacuum howver increases the sealing of the rings, and reduces blowby.

if you want oil out of yoru intake, just run your breather line down and out of site so it doesn't spew all over your bay. (at least until you get a cheapy catch can from ebay, or better yet spend 5 bucks for a cheap carberated fuel filter to catch the oil)

[manybrews]

as said, capping the breather caused it.

The PCV system is one of the most important emission systems on your car, not just in terms of reduced emissions, but its also one of the most helpful devices ever installed on an internal combustion engine. It helps remove moisture, fuel vapors, and many other contaminates INSIDE your engine that can cause damage.

people that run a seperate "breather" on their valve covers are also rather silly, as besides polluting the air, all they do is allow oil vapor to spew all over the valve cover.

during idle, nearly 25 percent of the airflow comes THROUGH the pcv system! that air NEEDS to be metered AND filtered. that is why the air breather attaches to the intake pipe between the airflow sensor and the throttle body.
Under WOT, the PCV valve shuts, and the vapor is forced out the breather where fresh air was pulled in previously. That vapor is pulled into the engine through the intake system and throttle body.
its SUPPOST to be that way, and altering it NOT GOOD.

[DOHCstunr]

yeah i made a cheapy catch can to keep the oil from gumming up the inside of my intercooler and reducing its efficiency. just a simple fuel filter to catch the oil and acids.
but its an inline filter and the other end of it goes back into my preturbo intake track.

when i hit boost that pcv slams shut, there is a great deal of pressure in the case at 7500rpms.
i've had to clean out the charge pipes and intercooler before. its a mess.

[98ACR]

I think there is a slight misunderstanding. I never had the PCV system closed. All I blocked off is the secondary breather tube, the one that goes from the valve cover just behind the distributor to the rubber intake tube. I did this because I found that rubber tube full of oil. So, for nearly 2 years I had a little breather filter on there. But it had become saturated in oil, so I just blocked it off. I've put the filter back on, but I refuse to suck that much oil into my engine. I'm probably going to route it so that it's connected to the PCV system through the catch-can.

[DOHCstunr]

I think there is a slight misunderstanding. I never had the PCV system closed. All I blocked off is the secondary breather tube, the one that goes from the valve cover just behind the distributor to the rubber intake tube. I did this because I found that rubber tube full of oil. So, for nearly 2 years I had a little breather filter on there. But it had become saturated in oil, so I just blocked it off. I've put the filter back on, but I refuse to suck that much oil into my engine. I'm probably going to route it so that it's connected to the PCV system through the catch-can.

ok so let me get this straight so we can be perfectly clear.
so you blocked off/ sealed the little nipple on the side of the valve cover?

[98ACR]

<div class='quotetop'>QUOTE(DOHCstunr)</div><div class='quotemain'>
ok so let me get this straight so we can be perfectly clear.
so you blocked off/ sealed the little nipple on the side of the valve cover?</div>

Yes, and also the nipple on the intake hose that is the corrolary to that nipple. Now the intake side is still sealed and the VC side has a breather. But oil is getting all over the distributor, so for the time being I'm gonna just put the damn tube back on there until a more elegant solution is engineered.

[manybrews]

<div class='quotetop'>QUOTE(98ACR)</div><div class='quotemain'>I think there is a slight misunderstanding. I never had the PCV system closed. All I blocked off is the secondary breather tube, the one that goes from the valve cover just behind the distributor to the rubber intake tube. I did this because I found that rubber tube full of oil. So, for nearly 2 years I had a little breather filter on there. But it had become saturated in oil, so I just blocked it off. I've put the filter back on, but I refuse to suck that much oil into my engine. I'm probably going to route it so that it's connected to the PCV system through the catch-can.</div>
yes, you DID have the PCV system closed. By blocking off the breather tube, you effectively sealed ANY way for air to enter the crankcase.
the rubber tube is SUPPOST to be "full of oil". incidently, its not "full" of oil, but has oil vapor in it, just like its SUPPOST to.
that oil is going there for a reason. dont use an asinine "catch" can or anything like that. the oil vapor will be burned as its suppost to during normal engine operation.
you cannot eliminate the oil vapor, nor would you want to or should you even try to. its a normal byproduct of all internal combustion engines, and has been for a hundred years. routing it into the intake piping allows it to be pulled, filtered and combusted when the pcv is in negative pressure, and allows it to be pushed and be combusted during postive pressure. that oil vapor is there all the time, being burned even when the PCV is in negative pressure. Its just being pulled into the engine via a different route.
incidently, unhooking the PCV system and venting it to the atmosphere is far, far more damaging to the engine over its life than leaving it hooked up as designed, as you are not allowing combustion gases, water vapor, and other contaminates to be pulled out of the crankcase and be burned. rather, they contaminate the oil and pollute it, raising the acid content of it.
Hook the PCV system back up as its suppost to; you gain nothing by venting it to atmosphere.