PLEASE HELP Oil Separator 2001 4.4 X5 (FIXED w/ lessons learned!!)
 

So I had the dreaded O.S. issue here in freezing Buffalo, NY on my 2001 4.4 X5. I read and read on here and had the typical symptoms. I removed the old O.S. and hoses and they were full of white sludge and the hoses were soft and deteriorating. I also changed the Valve cover gaskets. After I was done I took it for a ride and SES light was still blinking and it ran like crap! Same symptoms only worse misfiring and shaking. So I thought maybe I fouled the plugs. Changed them and still bad. NOW WHAT??!! Coils, Worse? Someone please help before I have to drop it off at the stealer. Thanks.

I had the same symptoms.... can shaking, misfirinng and SES blinking... turns out it is a low engine oil level.... Try to add a half bottle of oil and look how your car will behave.

Just my experience...

Best thing you can do now is double check your work and have the codes read from your local auto parts store before you goto the stealership. Symptoms are helpful, but in your case, codes will help more.

Oil level? That seems strange. But who knows. I'm having my brother Ohm out the coils tonight and going after bad coils now. I am fed up with this problem and hope this is it!!

Pull the codes as James said. It will make your life easier...

As for oil level...unless you have 'low level' warning I doubt that's the issue. But it helps to double check

Best of luck to you

In addition to getting the codes read and rechecking your work and the coils, check the CCV if it's original.

Did you replace the crankcase vent valve (attached to the rear of the intake manifold)? It might look okay on the outside, but the rubber gills on the inside are probably all clogged up like the OS. There is also a small oil vent hose that runs under the intake manifold to the CCV.

The intake manifold and throttle control gaskets might need some attention if they original.

Get the codes read and please report back.

Many of us here are like CSI--we want to know the outcome.

Make sure your MAF is plugged in and clean. Also your oil separator hoses might not be tight cousing a big vacuum leak?

FIXED!!!!!!!!!!!!!!!!!!!!!!!!!
 

After changing the O.S. and 2 sets of plugs and 2 weeks of paying for a rental car I'm out of the woods. It was 1 single coil. My brother OHMed out the coils and they checked good. So he then suggested checking them "oldschool" by removing the plugs one by one and with the coil hooked up, ground the plug to the engine and start the truck. Whala! The first plug we checked had no spark! We changed that coil and spark checked it. So after all that aggravation and money, it was one stupid coil. Although I am glad I changed the O.S. and all hoses, as they were in really bad shape.

MY CONTRIBUTION TO THE O.S. DILEMMA:

No where on here does anyone mention removing the housing for the cabin microfilter (middle part of the firewall). It's only two nuts and makes accessing the O.S. and hoses ten times easier. INTAKE MANIFOLD REMOVAL IS UNECESARRY!!!!

Also: DO NOT follow the DIY on the home page for the Oil Separator on this home page if you have a 4.4 like me. It's not even close to the required procedure!!

Congrats on getting it fixed. I've rarely heard of coil failures, but it can happen. Good job :)

Did u change your cabin filter? These m62's are always a pleasure to drive. Try and purchase bentley manual, it's full of helpful diy's