Crankcase ventilation/Oil Separator Mod - PeachParts Mercedes-Benz Forum

#1 09-01-2006, 12:04 AM

I got a free air line water/oil separator from work. The bowl has a small crack and hissed with the 160psi line pressure. It works with centrifugal force and a porous plastic filter.

So far it's working pretty well. After a hard run to get the engine hot, it no longer looks like I have a steam engine under my car. The exit is still vented to the atmosphere until I'm satisfied the system works. The air cleaner and u-tube are from a 79 300SD (The reason for the lack of an CCV port in the lid and the plug in the u-tube.)

It's already gathered a few drops worth of oil, but it's only been on for 30 miles.

bgkast · #2 09-01-2006, 12:51 AM

Cool. What do they cost for us people with-out such job perks and where can we get one?

Did you just have the hose venting to the atmosphere before you put it on?

Johnhef · #3 09-01-2006, 12:54 AM

Where do you have your drip tube attached to?

edit: duh same spot as mine.. for some reason I was thinking you had a 116 SD engine

#4 09-01-2006, 01:05 AM

Quote:

Originally Posted by bgkast

Cool. What do they cost for us people with-out such job perks and where can we get one?

Did you just have the hose venting to the atmosphere before you put it on?

In the $60-100 range depending on size and brand.
Yes, it was the same as now, just no separator.

Quote:

Originally Posted by Johnhef

Where do you have your drip tube attached to?

edit: duh same spot as mine.. for some reason I was thinking you had a 116 SD engine

Actually, I have the drip tube going into a pepsi bottle sitting in the old A/C receiver/dryer hole.

I just want to see how much oil it removes and how well it drains. (And it's a 300SD/300TD combo engine, BTW.

)

PanzerSD · #5 09-01-2006, 01:08 AM

By the looks of your Oil cap you got some good blowby happeing!

but the Oil separator idea is pretty ingenious! I'll have to try that!
I HATE how oil seeps from my aircleaner and fouls my nice clean turbocharger!

bgkast · #6 09-01-2006, 01:16 AM

Spendy. Next time you find a cracked one send it my way.

Admiral Ahani · #7 09-01-2006, 04:22 AM

I've been looking high and low for a used 240D oil separator to no avail. I'll try finding one of these now!

#8 09-01-2006, 09:47 AM

Quote:

Originally Posted by Got_The_Benz

By the looks of your Oil cap you got some good blowby happeing!

I solved that by cutting a new gasket and installing it on top of the existing gasket. The original gasket seems to just dry out and leak. I should just order a new one sometime:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1CQ0J3JZ41VY0KXEPH&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1982&product=A6150-64628&application=000001211

BioBens · #9 09-01-2006, 10:28 AM

[QUOTE=Got_The_Benz;1263894]By the looks of your Oil cap you got some good blowby happeing!

Oil seeping from the filler cap's an indicator of blowby?

#10 09-01-2006, 10:35 AM

Quote:

Originally Posted by BioBens

Oil seeping from the filler cap's an indicator of blowby?

Usually its just an indicator of a worn out cap gasket, or possibly a restriction in the vent line. All engines have some blowby, it should vent through the vent line, and the cap should be more or less leak tight.

#11 09-01-2006, 07:22 PM

Quote:

Originally Posted by BioBens

Oil seeping from the filler cap's an indicator of blowby?

Not really. Just a leaky seal. I wiped it off and put some new wheel bearing grease on it today. That should last for the next few oil changes. Doing the cap dance test makes a little jiggling with the breather plugged.

I'd be all over a 240D oil separator, if I could find one. Unfortunately my 80 was too early to have one as stock equipment.

The stock setup inside the aircleaner works OK, but I'd prefer my intake air to be oil free. When the VNT gets installed I want it to stay clean.

whunter · #12 09-30-2006, 09:19 PM

Quote:

Originally Posted by ForcedInduction

I got a free air line water/oil separator from work. The bowl has a small crack and hissed with the 160 psi line pressure. It works with centrifugal force and a porous plastic filter.

So far it's working pretty well. After a hard run to get the engine hot, it no longer looks like I have a steam engine under my car. The exit is still vented to the atmosphere until I'm satisfied the system works. The air cleaner and u-tube are from a 79 300SD (The reason for the lack of an CCV port in the lid and the plug in the u-tube.)

It's already gathered a few drops worth of oil, but it's only been on for 30 miles.

Warnings:

oil tube
http://www.peachparts.com/shopforum/diesel-discussion/85164-oil-tube-post552609.html

I removed my oil separator!
http://www.peachparts.com/shopforum/diesel-discussion/110491-i-removed-my-oil-separator-post770906.html

The oil separator has three legs.
#1. Crank case vapor pressure output...
#2. Vent to intake air, (draws off pressure).
#3. Oil return line, (pressure neutral, gravity feed).
Loose any of these, and it will damage your engine.

* Lose #1 and spray oil out, potentially until the engine is empty.
* Lose #2 and build crank case pressure until you blow enough seals/gaskets to relieve pressure.
* Lose #3 and drain oil out, potentially until the engine is empty.

Look at http://www.924.org for an alternative 924T air/oil separator.
http://www.924.org/parts/PartsPics/931_oil_separator2.jpg

Lingenfelter Oil Air Vapor Separator Replacement filter element
http://www.lingenfelter.com/store/ln-tt33fl.html

Moroso Oil/Air Separator
http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?storeId=10001&catalogId=10002&catalogIdentifier=Jegs_Direct&categoryId=78209&parentCategoryId=10475

Have a great day.

bgkast · #13 09-30-2006, 09:32 PM

I think that you would have to be very inattentive and have an engine with significant blow-by to loose enough oil to cause engine damage.

My airplane separator is working fine after several hundred miles. There only the slightest oil film in the intake vent tube.

whunter · #14 09-30-2006, 09:41 PM

Quote:

Originally Posted by bgkast

I think that you would have to be very inattentive and have an engine with significant blow-by to loose enough oil to cause engine damage.

My airplane separator is working fine after several hundred miles. There only the slightest oil film in the intake vent tube.

Yours appears to be correct.
My concern is for those who fail to understand the routing/function of the air/oil seperator/crank case vent.

Several members have:
#1. Plugged the CCV and drain tube, this caused seals to blow out, thus massive oil loss.
#2. Connected the CCV and drain tube with no vent, this caused seals to blow out, thus massive oil loss.
#3. Plugged the drain tube, and dropped the CCV down the back of the engine to drain on the road.

#15 09-30-2006, 09:47 PM

Quote:

Originally Posted by whunter

* Lose #1 and spray oil out, potentially until the engine is empty.

* Lose #3 and drain oil out, potentially until the engine is empty.

In a month, I've collected 3oz of oil from the crankcase fumes. Even still, I have run without ANY oil separator, just a tube going straight to the atmosphere/road for over two years with NO problems.

I very much doubt I would (or could) run my engine dry of oil if any of the tube s come off.