What is this Oil Hose? - PeachParts Mercedes-Benz Forum

EricSilver · #1 03-28-2011, 03:14 PM

1995 E320

What is this oil hose?

It is below and behind the water pump, one end attached to the assembly the tensioner, water pump and PS pump connect to; and the other end turning up to the head/intake.

I spayed it yesterday with brake parts remover and it was dry and gray. Now it is wet with oil again. I have noticed it for a long while but never assumed an oil leak.

Ferdman · #2 03-28-2011, 04:29 PM

Eric, difficult to determine from your picture, but I believe that's the oil return line. I replaced the oil return line on our 1995 E320 a couple of month's ago because it was leaking. Does it have a hose clamp on either end? If so, buy a new one (it's a shaped line) from your local MB dealer. From your picture it looks like someone used a piece of straight hose in place of the correct rubber part. My old one had cracked above the lower hose clamp and was leaking.

When installing the new oil return line I used adjustable hose clamps because I don't have a tool to remove/reinstall the spring-style MB hose clamps.

EricSilver · #3 03-28-2011, 04:51 PM

Fred -- I could not get a good picture because of its position, and the other hoses/wires in front of it, but it is indeed shaped and has clamps at both ends. (I looked in FastLane but don't see it.)

How complicated a task is it? The clamp hidden in the photo appears to be very unconventional. I will try to get a better picture.

Ferdman · #4 03-29-2011, 12:28 PM

Eric, the most difficult and time-consuming chore for me was removing the original hose clamps since access is tight. Once they were off it was a simple matter of installing the new return line and hose clamps.

Doubt that any aftermarket companies make the return line. Buy a new one from your local MB dealer. Our local dealer happened to have one in stock, but the Parts Dept. tech mentioned that it was the first one he had ever sold.

Jim_P · #5 03-30-2011, 09:36 AM

It is a crankcase vent hose that runs from the accessory bracket (bracket is hollow and has a gasket between it and the block) to the underside of the upper intake manifold. there are two fo them attached at the top. One goes to the lower intake and the other attaches at the location it the photo you took. The two of them will run you about $15 from the stealer. I just replaced both of mine as they were hard as a rock and I was unable to re-attach them when I swapped the motor in my C280. Just retain the old clamps as new ones are not included. Just pry the old hoses off with a long screw driver and the new ones will be soft and push on with a bit of effort. Not a huge job.

-Jim

EricSilver · #6 03-30-2011, 02:49 PM

Fred & Jim -- thanks.

It it leaking pretty badly on the bracket side but is dry at the manifold. Both ends have squeeze/compression clamps.

How much oil flows through there for it to leak so profusely?

EricSilver · #7 03-30-2011, 06:49 PM

Also -- it seeped previously but I think I may have made it really leak by cracking it when I replaced my water pump about a month ago. (I have not touched it so I don't know how soft or brittle it is.)

But if oil is accumulating in it, does that not suggest some other issue -- something causing oil to blow into it?

Ferdman · #8 03-31-2011, 06:58 AM

Eric, I have no idea how much oil flow or pressure is in the return oil line. While I had my 1995 E320 in for state inspection I pointed out the leak to a tech and he told me the function of the line. Previously I had looked unsuccessfully at various aftermarket websites for that particular hose/line.

You might try calling your local MB dealer and see if a Service Advisor/Supervisor can provide some detailed information and pointers.

EricSilver · #9 03-31-2011, 07:46 AM

This appears to be the hose -- and they have it here in Fastlane:

Picture
http://img.eautopartscatalog.com/hires/W01331633117VCO.JPG?width=300&height=300

Description
http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1995%40%401995&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6392%3ABT|5%3AED|10000022%3AMBC|1508%40%40E320+Sedan&keyword=breather&subcatid=W0133-1633117@@Breather%20Hose&mode=PA

What I am not clear on is which direction the oil is entering from -- top down from the intake; or from the bottom? I am wondering is a valve or other component is clogged and causing that.

Searching on "breather hose" I did see it is a fairly common issue and the symptoms include an irregular, oscillating idle, which is something I noticed in the last several weeks since the leak became aggressive.

Ferdman · #10 03-31-2011, 09:33 AM

Eric, the links show a hose similar to the MB part, but the MB oil return line has 2 bends in it ... including a slight bend at the top where it attaches below the intake manifold. I guess a hose with only the 90 degree bend at the bottom will work, but it will have more stress on it than one made to fit exactly.

EricSilver · #11 03-31-2011, 09:39 AM

Quote:

Originally Posted by Ferdman

Eric, the links show a hose similar to the MB part, but the MB oil return line has 2 bends in it ... including a slight bend at the top where it attaches below the intake manifold. I guess a hose with only the 90 degree bend at the bottom will work, but it will have more stress on it than one made to fit exactly.

I don't think mine is a return line but rather is the breather hose with a single bend. I will have another look today but the Fastlane hose appears identical to what is in my photo.

Also, the hose in my car seems to terminate where it attaches to the accessory bracket. Again, I need to take another look to see if there is some other conduit at that point which continues elsewhere.