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crankcase vent valve

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I have oil on the top of my engine block on the right rear side.  I think I traced it to the crankcase vent valve.  


Anyone know how to replace this.  I can hardly see it past all the tubes.

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The "crankcase vent" is the AOS and is located on the drivers side of the engine.  The oil cooler is on top of the engine on the passenger side.  Another possible suspect is the oil sending unit, also located on the passenger side of the engine.

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Interesting that they (Pelican) show this part #99610704751, for both 911 and Boxster.  Yet when you look at the pics they have the 911 as a connecting elbow without the extra vent and the Boxster as a connecting elbow with the vent.

Look at "more info",  images, then either Boxster or 911 diagram.



Edited by fpb111
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I'm not getting this.  That part is not located there in the picture next to the AC compressor.  The crankcase bleeder valve is located on the intake distributor on the driver's side of the engine.  The plastic hose that it connects to comes from the AOS, also located on the driver's side of the engine. For my 99 996 C2...it does not have an external vent as shown in the picture.  I guess what it comes down to is what year, model and engine type are we looking at? And, I often find it helpful to cram my IPhone back into the tight spaces and take pictures.  Works really well for "seeing" what is back there.  Are you sure it is not leaking from a power steering hose?

Edited by DBJoe996
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Glad you got it sorted out!  I was trying to help out on the basis of your car as listed in your profile - a 1999 911 4 Cab, and the parts diagram at Auto Atlanta for 1999 models.  Strange that your AOS and/or crankcase bleeder valve is located on the opposite side (passenger side) of the engine.  I can't figure that out from the parts diagram and from personal experience.  Be that as it may, at least the dealer got it figured out.  Are you going to have the dealer do the AOS replacement?  Just wondering....

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I hope the dealer got the part right.  It would suck if the AOS was not bad and the problem was just having the wrong part.  The AOS was less than a year old.  Can someone else with a 99 go out and look at their engine and see what part is on there.


I did have them do them do the work.  They did  a bunch of other stuff to the car while it was there. They actually did not charge me any more than an indy would.  And I got a loaner for the week.  And they picked up and delivered the car. 

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Ok did some research and found out that the OEM Porsche parts manual lists 2 parts for this


996 107 047 51 - this is the one with the extra vent tube


996 107 047 00 - this is the one without the vent tube


It looks like the one without the vent tube is for the M96.03 - I assume this is a newer generation of the M96 engine?

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