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Discussion Starter · #1 ·
Ok; in search of the engineproblems; I have opened up the top lid of the engine, and taken a picture of it (attached). Now I would like to have one of you guys to help me identify where the hoses for sucking out the oil is.

Also, I would like a short description of the different parts and their use.

I'm quite (actually terrible) a novice engine technician, so that's why I ask this stupid question. Hopefully any of you will help me here.

Rgds,

AFX
 

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I don't think it is a problem with any hoses taking anything in, it looks like a vanos issue from the valvetrain below those intake pipes.
 

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you picture doesn;'t look too bad to me. I took my plenum cover off, just for fun, and there was a little oil residue in mine too. I've read that it is normal. THe parts you have the red dot next to are 1. an intake trumpet, this is a tuned pipe that leads to a throttle body. 2. a cyclone oil separator, and the crankcase vent hose from the valve cover to the oil separator. These oil seperators can fail, and allow a lot of oil into the engine, but based on your pic, i don't think that's the issue. I didn't see any symptoms in your original post, so i don't understand the suggestion for a bad vanos unit. There is a seal in the vanos that can fail, but that typically causes a LOT of oil in the plenum, usuallly leaking thru the intakes and into the air filter boxes. Do a search on "oil in plenum" and you'll likely find a lot of info and pics.
Mike
 

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Discussion Starter · #4 ·
mottati said:
you picture doesn;'t look too bad to me. I took my plenum cover off, just for fun, and there was a little oil residue in mine too. I've read that it is normal. THe parts you have the red dot next to are 1. an intake trumpet, this is a tuned pipe that leads to a throttle body. 2. a cyclone oil separator, and the crankcase vent hose from the valve cover to the oil separator. These oil seperators can fail, and allow a lot of oil into the engine, but based on your pic, i don't think that's the issue. I didn't see any symptoms in your original post, so i don't understand the suggestion for a bad vanos unit. There is a seal in the vanos that can fail, but that typically causes a LOT of oil in the plenum, usuallly leaking thru the intakes and into the air filter boxes. Do a search on "oil in plenum" and you'll likely find a lot of info and pics.
Mike
Mike,

That's the problem! I have oil in my left (standing in front of car) airfilter, but nothing in my right (no traces of oil on the right side). From my other post, DavidS and others told me that a hose of some kind that should take care of oil under the plenum cover, could be "blocked", so I'm looking for this error. Car has only a milage of 57' km, and had an old man as a driver previously.

So, what/where should I start looking?

The "top" red mark is for a hole that leads to a thin steel pipe that again is connected to a similar hole on the opposite side, and also a hole in the middle. But is this pipe connected to anything else? Cant access the back of the engine (as a terrible technician I am ouich ). What is the purpose of this pipe ?
 

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ok. I'd guess the oil separator might be bad. It is the round thing that mounts at the front of the plenum with a hose going into it. It should keep the oil out of the plenum. Assuming you don't have a warranty, that should be the cheapest part to fix.
Mike
 

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Discussion Starter · #6 ·
mottati said:
ok. I'd guess the oil separator might be bad. It is the round thing that mounts at the front of the plenum with a hose going into it. It should keep the oil out of the plenum. Assuming you don't have a warranty, that should be the cheapest part to fix.
Mike
Can I clean it? Saturday tomorrow (now), and my million dollar guess is that the local dealer DON'T have the part on stock. Soon I'm crying so load you'll hear me over there too.......
 

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The oil residue in the picture looks fairly clean. Is it so in reality?

It looks like you have oil residue a bit up onto the air trumpet outside walls too. Correct?

Is the oil residue on the trumpets clean or black?

Is the oil you found on the air intake filters clean or black?

If it is clean, I think the engine was overfilled with oil, and then it will not happen again unless you overfill.

David
 

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Discussion Starter · #8 ·
DavidS said:
The oil residue in the picture looks fairly clean. Is it so in reality?

It looks like you have oil residue a bit up onto the air trumpet outside walls too. Correct?

Is the oil residue on the trumpets clean or black?

Is the oil you found on the air intake filters clean or black?

If it is clean, I think the engine was overfilled with oil, and then it will not happen again unless you overfill.

David
1) Yes the oil under the plenum is clean.
2) Yes, there is oil on the trumpet walls closest to "you" on the picture
3) Oil on trumpets looks clean
4) Oil in left filter is NOT clean.

Can I make the entire area inside/under the plenum clean/dry? Also, David, you mentioned earlier that some hose could be blocked. Is this the same as mottati is talking about; the separator ?

Also; the "pipe" in the back with 3 connections to the housing (left, middle and right, in the back), what is the purpose of this? Can this be blocked? Cant see if there is another connection that leads anywhere else on the engine.

Is there a engine manual/instruction on the net?

/AFX
 

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That picture looks familiar. I had a very similar problem, see http://www.m5board.com/vbulletin/showthread.php?t=42013 and the attached pictures. Even the underside of the plenum cover was splashed with oil. At first I thought it may have been overfilled (by the dealer) because it read a little high on the dipstick, but the dealer claimed that was not the case. They ended up replacing the seals in the VANOS units (and the MAFS which got fouled) and that seemed to cure it. That was a little over a year ago.

My car is back at the dealer again now and bad oil separators are being blamed for repeatedly burning out the catalytic converters (see my post from today in http://www.m5board.com/vbulletin/showthread.php?t=55822). I actually brought it in for different symptoms, so I hadn't checked recently to see if there's oil buildup in the plenum again, but I would guess there must be if it's burning enough oil to foul the cats, and they think it's the oil separators.

- Dave
 

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DaveK,

You are the expert on this! Thanks for posting.

Was the oil residue you found it the plenum chamber clean too?

David
 

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AFX said:
1) Yes the oil under the plenum is clean.
2) Yes, there is oil on the trumpet walls closest to "you" on the picture
3) Oil on trumpets looks clean
4) Oil in left filter is NOT clean.

Can I make the entire area inside/under the plenum clean/dry? Also, David, you mentioned earlier that some hose could be blocked. Is this the same as mottati is talking about; the separator ?

Also; the "pipe" in the back with 3 connections to the housing (left, middle and right, in the back), what is the purpose of this? Can this be blocked? Cant see if there is another connection that leads anywhere else on the engine.

Is there a engine manual/instruction on the net?

/AFX
The main reason you want to wipe the inside of the plenum chamber clean, and the air trumpets clean is that you want to be able to see how much oil aerosols come into the plenum and from where.

I wouldn´t use any degreaser or detergent, just wipe with paper.


The hoses I was referring to in the other thread are the oil hoses leading from the oil separators down to the oil-sump. You can not see those in your picture, as those are blocked from view by the oil separators.

I think the "pipe in the back" is the vacuum connection to the fuel pressure regulator and brake servo.


Looking at the picture I notice you have a bit of oil coming out by the oil filler cap. This means either a worn gasket, or increased pressure in the crankcase.


If the pressure in the crankcase is high, then it is either because of a bad Vanos seal, or from bad piston rings / cylinder walls. Having read DaveK´s thread, I´d say most likely a bad Vanos seal.

The best place to get engine information is either www.bmwtis.com (operated by BMW NA, costs USD 25 per day but you can download a lot of useful stuff in that time), or to get a copy of the BMW TIS CD (repair instructions) and BMW ETK CD (parts catalog) from a popular file-sharing program.

Now, everybody, isn´t this a great forum?

David
 

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Discussion Starter · #12 ·
David & Dave,

Seems that I have to change some of my info.
I went out to the garage again, and checked the oil on the plenum lid and on the trumpets... I DON'T think I will call it clean...

I will clean everything tomorrow, then I will put in my new airfilters, use the car for some days and open up again. Also I'll prob order new vanos gasket and oil cap.

Me and my luck with buying cars.... grmf...
 

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Good, that rules the overfilling theory out. Actually it does not, because it could have been overfilled when topping up without changing all of the oil.
Never mind.

I´d definitely advice not to try to change any part of the Vanos yourself. it is not a DIY job (and it is not a job for anyone except an experienced M-mechanic IMHO). If your local dealer has a reasonably talented mechanic, who is willing to follow the TIS instructions step-by-step without cutting corners, it could work just as well.

I´d suggest you ask the fellow Norsemen on this board where the northernmost trusted mechanic is with a bit of Vanos experience.

As I mentioned in the other thread, I think you should let the seller of the car cover the expenses for this. Ask a lawer for advice.

David
 

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I guess it's a good thing to pop-the-top and make sure.

Thanks for the info!
 

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Discussion Starter · #15 · (Edited)
Re: Oil in my airintake ::::> Cleaning successful !

Well fellas, done some cleaning of everything from under the lid, hoses and the MAF's. Replaced both airfilter's.

Improvement is impressive! :7:

Did provoke the car a bit yesterday with several WOT's to rev limit, every time without "studdering" from the engine, and so far, no limb mode. Today, it's wet and a bit colder outside (abt 16 degrees) and will test to see if the cold start problems are gone.

As I was told earlier in this thread; the problem abt the oil is probably from Vanos and/or Separator, and will most likely return. But now, at least, I know why the car was behaving so stupid.
Anyway, I will by new separator's, they can't be to expensive. Next, I will have to investigate if the oil returns, and maybe do something with the vanos...

I will also follow up abt new MAF's with a friend working at Bosch here in Norway.

/AFX :flag:
 

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Discussion Starter · #16 ·
Ok; now I know that the cold start trouble is still there. But as soon as the first light on the rev meter goes out, the engine runs as a pussycat :cool: . Strrange...

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When you have driven it a bit, why not perform a DIY MAF test. Then you will know how successful the MAF cleaning was, and you get a baseline to compare with over time.

David
 

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I was burning a lot of oil, changed the oil separator and crankcase breather valves, so far so good (about 1000km's). I asked for the mechanic to check the Vanos seals, but he said they were fine... But I think my MAFS are getting long in the tooth, with cleaning and all, so just waiting for the Bosch/VW thread to pan out and replace the MAF.


The oil separator and breather valve's aren't expensive. Good luck!
 
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