SeaCoupe

Ok, I give up. I'm looking for my PVC valve and I simply can't find the bugger. It is not up at the valve cover.

Some of you may recall that I'm getting oil in the MAF. I think this is coming from the PCV allowing oil up the line.

I did go to a MB Parts shop to get a diagram, but nothing in the parts catalogue lists out as PCV. So maybe MB calls it something else.

Any help is appreciated.

E

Outland

Ed,

Check out this thread...

https://mbworld.org/forums/showthrea...ight=pcv+valve
More related to original problem, and less on this need to find it...

SeaCoupe

Outland, thanks for taking an interest in this. I think reading that thread has me more confused.

Here is some additional views of the hoses. My oil can only be coming from one of these two places. It can't be coming from anywhere else.


Here is the black plenum that rests above the S/C.



This picture shows what hoses attach to what.



The piece that these hoses attaches to is molded into that whole black thing. So I would have to replace the whole thing minus the actuator mounted on the end. (You can't really see that in these pics)

What do you think would happen if I attached the crankcase hose to the valve cover hose. I was reading about negative pressure, etc on another thread.

I have so looked for check valves etc, but no luck seeing anything that looks like a valve, or where the EGR is located at.

Argh!!!

E

SeaCoupe

Here is where I am at. After MUCH thought on this. I think the system is supposed to work like this.

Oil comes from the Valve cover opening. This oil is then put into the oil seperator, which is the black box that I have labeled with the openings. The oil is suppossed to be returned to the crankcase via the crankcase tube.

It is the seperator that is not working. The seperator is somehow not trapping the oil. So, I think I am going to put it together now. (Ported S/C is due back any minute now)

IF I get the same problem, and I'm sure I will, as I have not changed any components in the system, I am going to first try:

Capping of the outlets from the seperator. Then plumb the valve cover opening to the crankcase line. Do you think there is any danger from say, negative pressure? Will the crankcase end up blowing too much air into the valve cover?

If this makes the car run fine, then I will get a new oil seperator.

What do you think?

E

oel

Just a question, what's the "To valve cover opening" hose for? I noticed that mine is cracked? Anything wrong with that?

SeaCoupe

What year is your Coupe?

I think that it is to lower emissions. This hose is easily replacable without the help of a service tech. If your car is a 2002, can you pull it off and see if the valve train is putting out air at the exit nozzle?

Give me some time and I'll even post the part number you will need.

Ed

SeaCoupe

Ah hell, here is your part #

1110182982

E

oel

Thank..!!
I'll check it out later when I get a chance to.

Outland

I think youre on the right track Ed....although without looking at the unit, or cracking it open, I'd be leary about plugging a line. Any pressure in the crankcase, positive or negative is bad. Positive causes seals to blow, negative pulls oil out of the engine.

It still confounds me that they wouldn't a simple checkvalve and seperator... does that right angled nipple with the small vent line come off the main assembly? BTW, how much oil is in there? What about the sheer volume of oil in there, or older less viscous oil plugging the line fittings?

Still sick here. Now Daughter and Wife also sick. Son has moved to Grandpa and Grandma's house until its safe here. :-(

HeirKranz

i might have a oil backup problem myself, i have a bunch of oil going throughout my intercooler and coating the MAF---i was going to put an additional oil seperator on the line beween the crank case and the oem breather but not sure if that is where the oil is coming from---either way it is a problem right now---not sure if it is due to the constant high RPMs the engine is driven at either??? any one else put their own air oil seperator and seen any improvement???

SeaCoupe

man, funny thing is that this thread gets dug up and I still haven't fixed the problem.

I installed a Catch can from the Valve cover vent line. No oil comes from there. Actually I think the oil is coming from a assembly near the TB. I was actually going to clean the assembly this p.m. I'll take pics and post up.

John G is loaning me the W203 CD today so I can figure out what the assembly is.

As we get high mileage, more people are going to get this problem. Not a doubt in my mind.

Lets see if we can figure this one out.

E

Outland

The more miles an engine gets, the more blowby it has. I wonder of the reverse pressure that the supercharger causes is the reason youre getting oil near the TB? The higher the velocity, the more likely youre going to get oil. This was a huge problem on one of my motorcycles...it would **** oil all down the side of the motor after you turned it off, as the oil would flow down the TB and into the air cleaner.

SeaCoupe

I CANT replicate the problem while parked. I have disconnected the lines, looked, throttled, no love.

There is an actuator plate at the front part of the black plenum. I now wonder, if that plenum is sucking the oil UP from the cranckase in some type of condition. As in when the Actuator plate is in a closed off position? Then, when it is sucked up, it flows through the Air Intake. I did see a part of the W203 CD that says that plate needs to be aligned to the operation of the car by opening and closing the actuator hand. While I have had this problem for some time, the reinstall with the ported S/C didn't include this type of work

I think my next step is to try a one way check vavle, that allows oil to return, but stops the suction.

If anyone needs more info on this, let me know. Any ideas on what kind of a check valve to use? The hose is about 3/8 of an inch.

Outland

Technically, that's the one that you would plug a PCV valve into. In theory, this all makes sense, but what happens when youre under boost, and the check valve slams shut?

WHere is this thing breathing into? Is there an upstream line, prior to the boosted section? That would be a nightmare if oil ever got in there, but you still need to vent the engine under boost.

Where exactly are you finding oil? To me, that's the key. Are the hoses oily? Is the oil coming in prior to the MAF?

HeirKranz

im getting oil way before the MAF----car now has 130,000 miles on it though but i drive it hard and has running up to 11lbs of boost from the pulley kit.---have enough oil to coat complete tube and MAF sensor but not enough to show smoke. will look at it this weekend---it has been a gradual thing though, it didn't just appear