You have to take the engine cover off. Its towards the back of the engine if you're looking at it from the front of the car..

He is asking about the 3.0 L engine. Many of us get confused between the two engines when we talk about the oil separator. The oil separator for the 3.0 L engine is located under the intake manafold and thottle body. It is very hard to find/see unless you take off the intake manafold.

Cliff's notes: Do not pull the intake manifold to get at the separator. It is unnecessary. I have R&R'ed mine twice, and my manifold has never left the engine.


You do not need to take off the intake manifold to find/see/replace the separator on the 3.0i. Take off the air box, the silencer, and the throttle body boot. Remove the nuts/bolts that hold the vacuum manifold (gray box with lots of hoses and wires going into it, located under #7 in this diagram. Push it aside, and disconnect whatever electrical leads allow you to do that. There are several right there, and they are only long enough to get to what they are supposed to go to, so do not worry if you need to disconnect them. They are spring loaded and go back on easily.

With that out of the way, you should see, under the intake manifold, a black plastic part with several hoses coming off of it. That is #1 in this diagram.

There are two screws that hold the separator to the engine. They are not easy to get at, and the lower one requires taking of the throttle body (#5 here), which is held on by four bolts. Just take it off the block and let it dangle back towards the firewall.

If your separator has never been replaced and needs to be done, I would recommend replacing all of the associated hoses , 2, 3, 4 and 7 in that diagram, plus the distribution piece (#5 here, which comes with new #6's installed).

That is the entire system. It takes blowby gases, unburned hydrocarbon (all bad for the crankcase), funnels them into the separator which sends liquid oil back into the pan (hose that comes off the bottom) and gases up to the distribution piece to be sent to every cylinder to be reignited. A good way to tell if your separator is working or not is taking off #7 in this diagram and seeing if the insides of the manifold are covered in oily goo. If it is, the separator is not working right, as oil is getting sent back into the intake where it does not belong. This is usually accompanied by decrease in mileage, as the oil in the chambers forces the computer to add fuel via injectors to achieve the correct air/fuel ratio.

thanks for all the input guys! I bought my X almost 2 years ago knowing it was going to need maintenance. I bought it without warranty becasue I am very mechanical myself. I just figured it wouldn't need so many things all the time! They are a very quirky machine. Its almost at the point where I am scared to drive it because something might go wrong again. Its sad really because I get into my 94 jeep grand cherokee and it just goes and goes!! so you put out over $20000 for a BMW and then $3000 for the jeep and its more reliable? But I do understand the theory of more performance more maintenance! Thanks again guys!

And your jeep is slow, isn't it? I know it is; I have two v8 Chryslers and they are slow.

Yes its really slow!! but the only good thing about the jeep is that I am not scared of what will go wrong everytime I start and Drive it!

How long should replacement take, better to do it on ramps? Is that the best way to access it? Or does come from the top? Please help !! Thanks.

I have a stupid question.... what does the oil seperator do? Go ahead, make fun :-)

Reread post #13. :thumbup:

Thanks... I need to skim info less and read the whole thing.:wow: