Originally Posted on The J-Body Source by Kyle Strait - http://www.j-body.tk/wiki/LD9OilAirSeparator
Are you losing a quart of oil every month and have no clue why but know for sure it isn't leaking out and know for sure that it isn't getting burned?
General Motors decided instead of putting a Positive Crankcase Ventilation (PCV) Valve in the LD9, they put in an Oil/Air Separator. This is one of the number one replaced parts on the engine (according to my local Chevy dealer.) However this isn't the easiest repair to do. It involves pulling off your Intake Manifold. If you do not feel comfortable doing this swap, by all means, DO NOT do it yourself.
PARTS NEEDED
-
Intake Manifold Gasket P/N MS95839 (Felpro P/N ... I did not get an OEM gasket... if someone has this number I'll update this page)
-
Oil/Air Separator P/N 24574498 (best to get this from the dealer as I found that most part stores have no clue what this is)
STEP ONE
Picture 1
- Remove Intake tubing & plenum (Plenum bolts illustrated in Picture 1.) Inspect Plenum for oil. If there is no oil in there, chances are your Oil/Air Separator is good. But chances are there will be oil sitting in it, so you want to clean that out
STEP TWO
Picture 2
- Remove all electronic plugs and all hoses illustrated in green in Picture 2. Remember to pull the blue locking tab out of the fuel injector plugs before attempting to remove or you will break a fuel injector.
- Remove throttle cables illustrated in yellow in Picture 2
- Remove throttle body illustrated in blue in Picture 2
STEP THREE
Picture 3
- Remove Oil hose from engine illustrated in black in Picture 3 (the other end of this goes to the Oil/Air Separator)
- Remove Air hose from Oil/Air Separator illustrated in green in Picture 3
- Remove Intake Manifold illustrated in white in Picture 3
STEP FOUR
Picture 4
- Remove old Oil/Air Separator illustrated in Red in Picture 4 (Take note that the OIL line is illustrated in yellow and the Air line is illustrated in Green)
- Its highly recommended to clean your Intake ports on the head, the intake manifold, and the throttle body.
Picture 5
This is how it should look with the Oil/Air Separator removed and the Intake ports cleaned.
Reverse the process to reinstall.
Very informative,did not know that.
15.2@89mph 2.171 60ft. 9.830 1/8 R.I.P. "LULU"
i believe the Ecotec uses this also as its PCV system... but im not positive... i should hop on AllData and check...
i wanna add the whole process took me like 2 hours to do, and most of that time was used cleaning everything...
Is this a redesigned oil/air separator?Maybe it has more passages in it,because the stock oil/air separator is pretty much a hollow box.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
Correct term on the LD9 is CV(crankcase ventilation)as per Chilton's manual
15.2@89mph 2.171 60ft. 9.830 1/8 R.I.P. "LULU"
quote=ptrblkz24]Is this a redesigned oil/air separator?Maybe it has more passages in it,because the stock oil/air separator is pretty much a hollow box.
i dunno ... the one i put back on looked like the one i took off... i see how it works... but i cant see why it went bad... but i know it was cause i had a good quarter of a quart of oil sitting in the bottom of the intake plenum box a few months ago... so i took the air tube and angled it straight down, and i could see how much oil was pouring out of it every time i drove (i was losing a quart a month, and my motor has 15,000 miles on it) ... i have a wholesale account through the local Chevy dealer through the body shop, and they told me this part is ordered very often and my cost was like 22 bucks, and it has a built in gasket.
Grumpy McGrumpster(BIGGSZ24) wrote:Correct term on the LD9 is CV(crankcase ventilation)as per Chilton's manual
that makes sense since this isnt a traditional PCV system ... but i wonder whats the difference between Positive Crankcase Ventilation and just Crankcase Ventilation
I dont see how replacing it with the same piece is gonna fix your oil problems.Its not really a maintenance part because theres nothing inside of it that can fail.The only thing i can see failing is the gasket.Let me know how it works out for you.
Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust
i was thinking that too... but ive heard in a lot places over here that its replaced often, and then the dealership parts counter told me that she sells the part all the time...
i'll know in about two weeks if my oil is low... i'll cap off the air side and force the oil back in the block
The only part that could go wrong is the gasket. The other part is solid plastic, and only has baffles, nothing that I can see can go bad.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Difference between the CV and the PCV is, among other things, a valve.The CV system used in the 2.3 and 2.4L allows crankcase vapors to escape but does not introduce fresh air into the crankcase.The blow-by vapors are drawn into the oil/air separator through a hose from the timing chain housing.Crankcase vapors are passed through the oil/air separator into the air cleaner outlet resonator.The oil/air separator is attached to the engine block and returns any oil suspended in the blow-by vapors to the crankcase.These blow-by gases will then be mixed with the intake air in the air cleaner outlet resonator instead of the manifold.The blow-by vapors are then drawn into the engine by normal engine vacuum and burned by the combustion process.Also incoporated into the CV system is a CV heater assembly,a positive temp. coefficient device to prevent icing in the CV system.All this info is from the Chilton's manual.This is why alot of people put a small breather filter in the hose,to prevent that oil from returning to the crankcase in turn causing sludge buildup.
15.2@89mph 2.171 60ft. 9.830 1/8 R.I.P. "LULU"
yeah... that works ... we'll see what happens...
-MD- LD9 wrote:The only part that could go wrong is the gasket. The other part is solid plastic, and only has baffles, nothing that I can see can go bad.
Well this weekend I was working on the cav when I decided to lool at my Oil/Air separator....and well it was literly clogged with sludge, and white/yellow deposits.
The vacuum line from the intake to the oil/air separator was also CLOGGED.
So I replaced it with a spare one I had laying around. I then checked my oil to see if their was moister or condensation. Oil was fine.
Which further through me for a loop. I cleaned the one I took off, and everything was fine.....
But what would cause this..........Also the cav idles like a champ again.....compared to before. Also is burning
a lot less oil.....
Very strange... I'll have to keep in mind to check and clean this ever so often.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
might have to rip mine apart too.... my cars fuel economy has been sucking latley, but i think that has to do with the fact that my O2 sensor has 210 K km on it and hasnt been changed as far as i know.
either way this sounds like good basic maintenance and i would think as long as the gasket on the seperator isnt shot that it could be reused if you cleaned everything out nice.
1997 RedR - ZedR
This should be a STICKY, Its a part many people look at, and really dont think anything of it, this post can change alot of people cars for the better, im going to go check mine out to.
This thread has the pictures for the procedure:
http://www.jbodysource.org/wiki/LD9OilAirSeparator
This came off my car with 112,000 miles on it. Note you do not need to buy a new one, they can be easily cleaned out being they are completely open once removed. If you gasket is dry rotted you will want to buy a new one:
2000 Sunfire GT Convertible (daughters car, totaled Jan 2014 RIP)
I can't open any photos in this post... when I hit on it I get "does not exist or could not be found" Some one tell me what I'm doing wrong or have a 10 year old kid write me back with HOW TO"S
Thanks, JC
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This thread has the pictures for the procedure:
http://www.jbodysource.org/wiki/LD9OilAirSeparator
This came off my car with 112,000 miles on it. Note you do not need to buy a new one, they can be easily cleaned out being they are completely open once removed. If you gasket is dry rotted you will want to buy a new one:
