[Alexismeza]

Originally Posted by gbalthrop

Since BOTH banks have same codes, it would seem reasonable that the oil is being drawn in through the intake manifold (essentially ALL cylinders evenly receiving same amount of oil). Also, you do NOT have O2 Sensor fault ON DECELERATION which one would expect if bad rings.

Intake of oil from PVC & Valve Cover can be confirmed by removing the hose that draws crankcase vent air from the Valve Cover to the Intake Manifold. It should be QUITE soaked in oil at this point.

How many miles has the car been driven with the oil burning issue already? Or how many quarts of oil have you had to add? You DO risk damaging the cats by continued operation, and you are carboning-up your intake (which Techron added to gas may improve). Your car/your money, but I would change the VC (doing the job myself). The equation changes if you pay someone else $Labor$.

If you do your own work, the VC can be replaced for $300 to $400 max. If you do NOT do your own work, then consider getting something under warranty.

George

I haven't driven the car much. It's been an ongoing issue for a few months and over the span I've had to put close to 3+ qrts. Which steps can I take to make sure if I do replaced the valve cover to insure the car is up to spec? Any advise for when this gets done? How do you feel about the replacement kit?

[Makeuwunder]

You have been given some great information. the only thing I say to check is to be sure that this check cap is on the PCV vacuum. This missing can cause the car to run badly also. It controls the venting for the vacuum pressure. If it is present I would agree that you have a bad valve cover.

[Alexismeza]

Originally Posted by Makeuwunder

You have been given some great information. the only thing I say to check is to be sure that this check cap is on the PCV vacuum. This missing can cause the car to run badly also. It controls the venting for the vacuum pressure. If it is present I would agree that you have a bad valve cover.

Would you happen to know the name of this part? I checked on my car and didn't see it. It has a hose that's being routed to the air intake. I noticed that the intake itself is cracked has a crack. Would this cause issues with the PCV? I ordered the replacement kit for the PCV and it also didn't come with that part. Would are your thought of using the replacement kit for the PCV?

[Joebie]

Originally Posted by Alexismeza

Would you happen to know the name of this part? I checked on my car and didn't see it. It has a hose that's being routed to the air intake. I noticed that the intake itself is cracked has a crack. Would this cause issues with the PCV? I ordered the replacement kit for the PCV and it also didn't come with that part. Would are your thought of using the replacement kit for the PCV?

You need to fix whatever that hose clamp abomination in the first picture is. If that's an air leak, its a leak past the MAF which will give the engine more or less air than the computer thinks its getting and really mess with stuff.

Also if that's an air leak its sucking in unfiltered air which is also not good.

Forget about your PCV for now, this may be your whole problem if the air leak is bad enough.


Also in the first pictures, i see a DISA valve. Is your car an N51 motor? (SULEV?) Could it be possible that whoever replaced your motor put an N51 where an N52 used to be? When i was looking for a new N52, I found that most scrappers couldn't tell the difference. I almost got shipped an N51 actually.

[Alexismeza]

Originally Posted by Joester

You need to fix whatever that hose clamp abomination in the first picture is. If that's an air leak, its a leak past the MAF which will give the engine more or less air than the computer thinks its getting and really mess with stuff.

Also if that's an air leak its sucking in unfiltered air which is also not good.

Forget about your PCV for now, this may be your whole problem if the air leak is bad enough.


Also in the first pictures, i see a DISA valve. Is your car an N51 motor? (SULEV?) Could it be possible that whoever replaced your motor put an N51 where an N52 used to be? When i was looking for a new N52, I found that most scrappers couldn't tell the difference. I almost got shipped an N51 actually.

I'll look into getting it fixed before the PCV see if possibly that will resolve the issue. Yes the car does have the N51 (SULEV) vin (WBAVC73517KP31464). When I was looking for the car I had actually thought it had the N52 and was looking to purchase it but the seller had mentioned I had the n51. I believe he worked with BMW's so he was more informed.

[Alexismeza]

I've gotten the hose fixed & replaced the filter. Car is still running rich. although now I believe I need to change the plugs. ( I have a code for misfire Cylinder 6 & 4) I can also feel the car stumble when accelerating. I haven't gotten around to checking the plugs. I have the current codes and Freeze frame data and was seeing if anyone could give feedback regarding them before I change the plugs. I'm still feeling some of the symptoms with the PCV as well. Thanks in advance.

[gbalthrop]

Originally Posted by Alexismeza

I've gotten the hose fixed & replaced the filter. Car is still running rich...

I don't understand what you mean as far as what hose was fixed and what filter was replaced. Until you replace the VC (Valve Cover) which contains the built-in PVC valve, you are going to continue to have gross oil consumption, rich running, tail pipe smoke, and risk permanent damage to your catalytic converters.

A month ago you began this thread with the title "E90 is running lean." It has been explained by various posters in reply to your description of the issue that:
(1) it is NOT running lean, but the reverse of that: It is running RICH;
(2) it appears the cause of the rich running is sucking oil into the intake as a result of a bad PCV valve which is incorporated in your plastic Valve Cover (VC);
(3) risk of damage to the catalytic converters has been explained.

I realize that diagnosing and maintaining a vehicle can be expensive & stressful, and it is often difficult to be completely objective when your own vehicle, time & money are at issue.

HOWEVER, my advice today is the SAME as it was on 1/28/2019:

"Since BOTH banks have same codes, it would seem reasonable that the oil is being drawn in through the intake manifold (essentially ALL cylinders evenly receiving same amount of oil). Also, you do NOT have O2 Sensor fault ON DECELERATION which one would expect if bad rings.

Intake of oil from PVC & Valve Cover can be confirmed by removing the hose that draws crankcase vent air from the Valve Cover to the Intake Manifold. It should be QUITE soaked in oil at this point.

How many miles has the car been driven with the oil burning issue already? Or how many quarts of oil have you had to add? You DO risk damaging the cats by continued operation, and you are carboning-up your intake (which Techron added to gas may improve). Your car/your money, but I would change the VC (doing the job myself). The equation changes if you pay someone else $Labor$.

If you do your own work, the VC can be replaced for $300 to $400 max. If you do NOT do your own work, then consider getting something under warranty."

If you refuse to accept that you need to change the VC, AT LEAST remove the hose that runs from the rear of the VC to the intake manifold, and inspect for OIL in that hose.

George

[E90_slides]

Originally Posted by Makeuwunder

You have been given some great information. the only thing I say to check is to be sure that this check cap is on the PCV vacuum. This missing can cause the car to run badly also. It controls the venting for the vacuum pressure. If it is present I would agree that you have a bad valve cover.

can you provide any other threads or info on this? my vehicle doesn't have this cap and its had a rough idle for a while now but I replaced the VC and took this cap off thinking it was just a protective thing for shipping. could i use a rubber cap over it? or would i need to try to source this cap from somewhere?