Now How about a DIY Guide for OSV in 1995 540?

[Jehu]

I have been looking at this as a reason for using a quart of oil every 800-900 miles. I began looking into replacing it and so far think it involves removing the left valve cover at least. Also suggested was the removal of the Oil Filter Housing which is right in front of that valve cover.

Wondering if the left upper Timing Chain Cover would have to come off as well. I've seen an image of the part seated in behind the Timing Chains. I've found reference to its removal in the Bentley under Head Removal and it just says lift it out as part of the removal proceedure so I guess I could just follow that proceedure.

has anyone been down there either to specifically replace this part or torn the M60B40 apart to perhaps replace the timing chain guide rail or tenstioner who will comment? Thanks.

The one shop I contacted about doing this told me the Engine needed to come out... I don't see what he means .

[yaofeng]

I do not believe you have access to the cyclone from the top without removing the front timing cover. When I had my 66k M60B40 on the stand I removed the oil pan and turned the engine upside down. I did not even see the cyclone which is at the end of the oil tube in the pictures. I went as far as removing the oil pump to tighten the bolts. Then again I did not pay attention to the cyclone at all. There is a possibility after you remove the oil pump you can then get to the oil separator from below. But I would not know how having never attempted it.

http://www.realoem.com/bmw/diagrams/c/o/3.png

http://img834.imageshack.us/img834/5356/dsc2614.jpg

http://img594.imageshack.us/img594/9784/dsc2615o.jpg

[Jehu]

Yah.. I'm told the Lower TC Cover has to be removed. You can see it from just removing the valve cover and upper left TC Cover but apparently that doesn't give you enough room to reach for it and remove it...

If that's not the case I'd like to know because that is what I've being told which of course at $70/hr is not really within the realm of sanity for an engine with 275,000 or 375,000 miles on it depending on what actually gets done during the recall block swap.

Guess I'll have to live with it..

[leicesterboy15]

Looking at the diagram it looks like the OSV is what sends vapours back into the intake? If your PCV plate is good won't that stop the loss of oil anyway? Have you tried rebuilding your intake with new gaskets and a new PCV Plate? That looks to me like a much easier job to attempt first.

[Jehu]

The PVC plate or Intake manifold Cover as its sometimes called was replaced perhaps 18 months ago.

About three years ago i started leaking oil. The leaks are all fixed for a year and a half now but even after that I continued to need to add oil at the same intervals. I add a quart about every 800-1,000 miles and have since the leak appeared..

If the front OSV failed at one point allowing a sudden excessive rise in crank case pressure could that have damaged the Timing chain cover gasket? This was among a few other places where the leak was located. If thereafter the valve became unable to allow Oil to return to the crank case after it entered the OSV it would be drawn up into the Intake and while the PVC plate would still release air pressure any oil which made it that far would be deposited into the inside of the intake would it not? Once it leaked in it drips onto the valves, into the chambers and is burned during combustion.

I propose this hypothesis with no actual knowledge of the manner in which the OSV performs its functions when working properly. Maybe I misunderstand how the PVC plate design may or may not allow any wayward oil to enter the interior of the intake manifold .


I have an appointment at a pretty highly regarded independent BMW shop Dec 2nd to give it a look. They have stated this part can be replaced without removing the engine but they feel with the high mileage the Piston Rings may be cracked or worn and thus be the cause of my Oil Consumption. I understand this may be true now but whereas I have been using the same amount of extra oil for three years,beginning when the car had merely 150,000 miles I would be surprised if the Rings were the cause of the loss back then. of course the fact there was a leak can not be ignored but the fact remains that even after having the oil leaks fully repaired I still within the same interval as before found the Engine Oil Low Warning appearing just as it had while the engine leaked...

If I was able to know with a high degree of certainty just how much Oil Loss can in any instance be attributed to a failed Oil Separator valve this would aid my decision in how much I might be willing to spend to have a shop do it or if after discussing the job I find it is within my mental ability if not my logistical capacity I might seek out the place to do it myself..

In thinking all this through I had to ask exactly what got done by BMW when they replaced the original Nikasil Block.

I have been told two things. One was that EVERYTHING below the heads was replaced NEW. new piston rings would of course have been used. The second was that ONLY the Block itself and the head gaskets were new . Everything else from the block up was re-used..

The work was done as far as I can gather at 98,000 miles on the ODO. the leak began around 150,000. if the rings were in fact replaced at 98,000 that would seem to leave the likelihood they were the cause of the leak all along rather low. They may i suppose be a contributing factor by now though with the odo at 377,000.