Guys, what is this thing? I removed the plenum hose from the right hand side valve cover to find this. Is it the oil separator? I see no mention of it in the RAVE or on the parts list at rover north? How is it removed or is it? What is the best way to clean this if at all? My PCV system has reversed its flow and I'm looking at what I thought was the easy stuff first. Thanks!

 

If it looks like a plastic sculpture of a pasta noodle, that's the separator. Squirts clean with carb cleaner. Might break off if handled roughly.

 

Thanks Buzz. You were right! I used a vise grip so I could ensure when closed there was enough space to not crush the tip of the noodle (ha ha he he).

Here's what she looked like taken out:



Cleaned with a rag then carb cleaner. I'm hoping this will be the fix and get the airflow heading back in the correct direction. Thanks for your help Buzz!

 

In Rovers North it is called a spiral separator and it part of the top end valve cover breakdown

 

How did you know your PCV system had reversed it's flow?

 

caymandrew posted this photo on another thread




It is important to note that it is normal for the PCV to reverse flow under certain conditons, like WOT. But when oil separator is blocked with gunk, all flow will be toward throttle plate. It also makes a slight pressure inside the oil return spaces of the motor, and some seals can vent oil. When cleaning this with carb cleaner spray don't forget the back side of the butterfly plate, and there is a ridge that allows a pool of fluid to form behind the plate, this can be soaked up with a cloth rag. Don't put paper towel back there, it can tear off and go into the intake.

Note if the oil mist is this color, wonder what the rockers look like? When you do a SeaFoam induction teatment, this is the kind of stuff it solvents and "smokes out". The PCV system could be an indicator of other oil system issues. If the passages from the heads that drain back to the oil pan by gravity have that kind of sludge build up, the oil pump can starve at higher rpms, as too much oil stays too long in the rocker covers. SeaFoam or BG treatment in the oil, Rotella with frequent drain and refill, etc.

Now don't think that the dirty old 1960's Buick engine is only capable of plugging up that plastic noodle. That's the tip of the iceberg. There will be more sludge. Here are some pix of places it can hide. The clean drive train pix shows one of the galley drains.

 

It all started here when Buzz explain how the airflow should travel:

That's when I recalled what my throttle body (above) looked like before I cleaned it.

Buzz, I've done a couple engine flushes and on the last one my Rotella was very clean, just had a the red tint from the gunk flush in it. So I think I'm ok on the inside. Only using rotella 15w40 now. Quick question, aside from back feed into the throttle, is there any way to verify the air flow is now working correctly?

 

In the first picture, isn't the oil separator installed upside down? I thought the open end of the metal tube is supposed to press into the valve cover, and the closed end of the metal tube with the small hole is supposed to face up.

 

Earlier trucks, I believe all the 4.0s, do not have a closed end. It's just a tube in the valve cover, the cap was added later in production.

 

re: is there any way to verify the air flow is now working correctly?

Should be a slight vacuum at the passenger side line when it is unplugged from your now cleaned up oil separator. Would think also a slight vacuum at driver side line when taken apart from throttle body. The intake vacuum is pulling air from the throttle body on the air filter side thru the motor and into the intake. Mine reads like 3 inch of vacuum on the hose from the driver side valve cover. Just now when starting to test the passenger side half of my oil separator "separated", so at the moment I don't know if it falls all the way into the works or is trapped by an internal baffle. Only half came out.

Update, there is a metal bafflr below the tube. I guess I just had a partial one. I had placed a rubber elbow on it and that has tuned to mush, which has my reading skewed. I get 17 inch of vac on teh passensger side, toward intake (expected); but only 5 or 6 on driver side. Will replace hose elbow and retest. I think the vac is collapsing the elbow.