Crankcase breather question (with pics)

[Jim Gains 05]

Hi folks,

I have a crankcase breather question I thought someone might be able to shed some light on..

The car is a '93 Plymouth Acclaim (2.5 4 banger) in Tampa, Florida with 105,000 miles. After taking the air filter assembly off of the engine to replace the PCV valve, I noticed the crankcase breather hose was split and the nipple on the air filter assembly (the hard molded plastic) was completely cracked and split open..









Here you can see the connection on the engine side:





And a little of the orientation in relation to the engine...



Other pics...



My question is this...do I really need to hook the crankcase breather hose back into the air filter assembly? It is throwing out some hellacious hot gases with a good amount of force from the crankcase (and some very slight oil spray) right into the air filter assembly.. Now I know this is done for emissions purposes, but is it necessary for proper engine operation?

The engine seem to run fine with it disconnected, but I wasn't sure. It seems like some folks go out of their way to get COLD air into the intake, not boiling hot air expelled from the crankcase.

Can someone clear this "newb" question up for me?

[ August 01, 2005, 03:46 AM: Message edited by: Jim Gains 05 ]

 

[kenw]

It's not the liquid oil they are trying to catch, it's the gasses. The breather used to be vented to atmosphere anyway.

 

[mechtech]

Sure, you can vent the inlet elsewhere.
You can get a little filter that will clamp on the inlet, at an autoparts store. Looks like a mini K+N.
You DO want a filter on the inlet side of the PCV system - don't just leave it open.
Factories want the hose to the air cleaner, so that when the engine is off, or under load, the gasses are trapped/recirculated.
I've seen plenty of air filters soaked with oil from PCV hoses.
Don't forget to plug the hole in the filter housing.

 

[Gary Allan]

You don't know the rational that some of the Chrysler engineers used in designing this setup. My 2.5 jeep engine also has a high volume output of crankcase emissions at idle. It also has a oddly configured throttle body plenumn. I don't know how they produce non-oil saturated emissions from the valve cover since the only source that should be involved here is blowby

Mine appears to provide a chamber for any heavy oil vapors to deposit ..and drain back to the valve cover.

I would hit up a U-Pull-it and get a new air box and restore it to its OEM condition.

Chrysler appeared to be able to get away with this modified road draft tube during this evolution. Basically they ran the (normally) air inlet to the crankcase to a foam baffle outside/down stream of the air filter. In my Caravan (3.0) if it saturates the foam pad thingie ..it coats a small portion of the air filter element. If blowby is so excessive that it produces too much oil ...it merely drains out of a seperate tube onto the exhaust manifold

Not a very environmentally sound design.

 

[The_Jeff]

There should be a little foam breather filter in the bottom of the airbox. It'll be so grime-ified if it's still present it'll block all airflow, popping that hose off.

If this foam breather filter goes missing, oily fumes will puke onto the regular air filter. Also when that hose draws a vacuum it'll ingest dirt.

It's a little foam square that'll probably run $.97 for a cheapo fram.