Oil in the air filter. 617 engine. More than normal. - PeachParts Mercedes-Benz Forum

dmorrison · #1 11-12-2004, 09:33 PM

Had an oil leak and thought it was the turbo oil line going to the oil pan.

Advise on instaling large oring on airfilter to turbo tube.

Found the orings and seal a little hard but not terrible. So at least that is done for the next 7 years. Did the job 7 years ago.

Removed the air filter to completely check for the oil leak. Wanted to make sure the air filter oil seperator was seated in the drain tube. Seems the air filter had a lot of oil in it. The oil was located in the housing on the inside of the removable filter and had leaked down to the outside of the removable air filter. So the air filter was covered with a little oil. I would say about 1/2 oz. was in there.
Looking at the oil seperating assembly inside the air filter I have a couple of questions for the group.
I had removed the cyclone seperator by bending the tabs and cleaning it out. all the oil seperating work is done in the cap. The metal section is just a cone shaped drain.
The plastic top connects to a 90 degree drain tube that drains the excesses gasses into the intake.
I found the 90 degree tube to be loose connecting to the top. No O ring just a little loose ( can't buy just that part, have to buy the whole air filter assembly from the dealer). Used bedding and glazing compund to tighten the connection. Used this just incase some slides into the turbo. I doubt it but it never drys and is plyable. The turbo would pass it. But once this stuff sticks to the material it takes a lot to remove it. Usually gas or 3Mweather strip adhesive remover. Used this extensively in the 65 Mustang, and its sticky stuff.

Went to the dealer and talked to ther W123 specialist. They suggested a couple of things.
Use a Mityvac to check the drain tube going to the oil pan. There is a 1 way check valve in the upper oil pan where the drain tube goes into the oil pan. Its is designed to prevent oil in the oil pan from being sucked up into the air filter. However the experienced mechanic I talk to has never had to replace the check valve. I'll check that out tomorrow.
Second I mentioned sealing the top of the cyclone seperator with the bedding and glazing compound, he said it couldn't hurt.
He also recommended replacing the valve cover to airfilter blowby tube. I tend to think is the main oil leak. I cleaned everything yesterday and openned it today. I had a small amount of oil in the assembly. There seemed to be some oil that shows a flow path from the valve cover tube where it attaches to the seperator. So the new tube I purchased will be installed tommorrow and I'll keep checking it.

Anything else you guys can think of with this problem???

Dave

rgp123 · #2 11-12-2004, 10:05 PM

Dave, can you enlighten me on the proper connection between the bowl-shaped drain and the drain tube? I was getting a vibration that I passed off to a broken breather mount. When I took off the assembly it was a loose nut inside and the culprit was the drain tube in its disconnected state. I just came by this car and have no idea how long it's been this way. The oil leakage on the turbo, exhaust and engine was horrible. It seem like 2-3 oz. every time you drove the car! I fabbed a little "nipple" from a flared piece of copper tubing, half-inch in diameter and about three-quarters of an inch long, to keep the drain tube in place.

Am I missing something here?

Rick

dmorrison · #3 11-12-2004, 11:32 PM

The oil separator tube is at the bottom of the air filter. This tube section should have an Oring on it. Available at the dealer. This tube goes down to the upper oil pan and that is the check valve I was talking about.
This site shows the engine crankcase ventalation. Your car will ebthe second engine. The diagram does not show the air filter oil separtor drain tube. It does show the tube ( #6) that it attaches to.

http://skinnerbox.steaky.org/Service/W123/w123CD2/Program/Engine/617/01-040.pdf

Dave

rgp123 · #4 11-13-2004, 09:00 AM

I will check for the correct part. In the meantime my rig seems to be getting the oil down the drain.

kerry · #5 11-13-2004, 07:52 PM

"There is a 1 way check valve in the upper oil pan where the drain tube goes into the oil pan. Its is designed to prevent oil in the oil pan from being sucked up into the air filter. However the experienced mechanic I talk to has never had to replace the check valve. I'll check that out tomorrow."

The existence of this valve is important. In discussions of high oil consumption in past threads, some people have denied the existence of such a valve. I believe it is important to raise awareness of its existence. If this valve fails and pressure builds in the crankcase I think it is possible for oil to be forced into the intake.

dmorrison · #6 11-13-2004, 08:46 PM

This valve is mentioned the 617 manual under rebuilding the engine.
As I said, the experienced mechaninc I know and trust at the dealer has never replaced one.
the check is simplet. Use a Mityvac in the oil seperator tube. Seal it, I know my rubber tube on the Mityvac is smaller than the drain tube. Then pump away. YOu should be able to hold a vacuum. If not the replacement of the valve is done by dropping the lower oil pan.

I did not get to vacuum test the valve today. I got busy and then
had to watch Texas A & M "beat the hell out of" Texas Tech.
Also spent a hour trying to post the pictures of the 617 engine manual job 01-415 that had the missing steps. Never did get it to post properly. Michael LaFleuris trying to rebuild his engine and steps 36 through 42 are missing in the CD but in the paper manual that I have.

Dave