E90 PCV valve replaced without removing valve cover

[Midyetta]

After performing a smoke test, I located the common leak that develops within the PCV valve located on the valve cover near cylinder 6.

Has anyone had success replacing this valve with the aftermarket part rather than replacing the entire valve cover?

[dworthy]

Welcome to the Forum!

Nope, but that is a common place for it to crack. The CCV is built into the valve cover, and at your age as I am guessing it's a 2010, you are about due for a new valve cover gasket too. I had just replaced one on an 08 last week, and it was a leaking mess, there was oil all over the motor, very hard to determine where exactly the oil was coming from.

[jclausen]

Google e90 pcv diaphragm

[Midyetta]

I am going to try just the valve replacement this weekend and see how that goes. If my code comes back (P2098), I will look at replacing the cover and gaskets next. I already replaced both bank 2 o2 sensors. After replacing those and still getting the code, I made a smoke test device and saw the smoke coming from the valve, so I know it leaks and it makes sense to me that that may very well be causing the code.

If the code returns, I'll do another smoke test before jumping to replace the cover. I just want my car to not have a light lol. It actually seems to run ok but I worry my cat and/or performance is being compromised.

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Thanks

[Midyetta]

Pcv diaphram job went well. I did not break any tabs (most all do in the YouTube vids). I let it cure with RTV sealant. Reset codes and went for a spin.

SES light returns... so I perform another smoke test and I cannot find any air leaks now.

Now, I did drive it with the leaking pcv diaphram (and it was destroyed by the way) for probably over a year. That is how long the p2098 code has been in effect.

I've replaced the air filter, cleaned the MAF, replaced both bank two O2 sensors. I have a Bluetooth odb and using the torque app, I can see my b1s2 and b2s2 real time data. No expert here, but the b2s2 fluctuates up and down at idle and maintaining speeds while my b1s2 is much more stable.

I have heard the MAF could be the culprit, but I have a hard time thinking the MAF is the issue when the code only ever indicates bank 2.

So now I am am looking at the cat. Any suggestions?

[dworthy]

What type of smoke machine are you using?

Also what is the code(s), word for word so we can see the other codes you do have.

Lastly have you attempted to clean the MAF?

[Midyetta]

Maf has been cleaned with MAF cleaner. The code is P2098: Post catalyst fuel trim system too lean.

The smoke machine is home made. It is made with a pickle jar, mineral oil and a rag used as a wick, a soldering iron, and an aquarium pump. I have hose running from an aquarium pump pushing air in and a hose running from the jar to the air hose after the MAF. I used a rubber glove to connect the air line to the intake hose. You can watch the glove expand as pressure builds.

When I first used the smoke device, it did not take long for smoke to spew out of the pcv diaphram. Now the glove blows up like a balloon until it pops.

Also, I pulled some spark plugs from both banks and they all look good.

The vehicle runs ok. I live in NC in a county that does not require emissions testing, so there is no dire need to fix the light aside from not having the light and also the hope that performance will improve ( not sure if performance is compromised).

[shadowpuck]

do you have the tools to do a back pressure test?

[Midyetta]

do you have the tools to do a back pressure test?

No? What does that entail?

[Midyetta]

I read about back pressure testing. I don't have a way to do that. The torque app option for exhaust gas pressure is grayed out.. unless I had instructions to key a special PID in the torque app for that, I'd have to purchase a tool.

[shadowpuck]

yup, i'd expect that a mechanical reading is the way to do it - at least, that's how i've always proceeded.....
if i recall it isn't that expensive....anytime i've suspected a cat issue on my car its what i've had done...

if you have pre-post cat o2 sensors that are basically mirroring each other, you have an issue.....

[White94RX]

Throw that piece of crap repair part in the trash and get a new valve cover.

[Midyetta]

Lol it seems to be working great but I can provide you my address and you can feel free to send me a new valve cover.

[White94RX]

It's working great, yet your check engine light is still on.....

[Midyetta]

It's working great, yet your check engine light is still on.....

I got on this forum to ask for help, not get smart a$$ replies. You have not checked my car. The air leak is gone. The valve cover is not leaking and the code does not specifically indicate that that is the issue. Go back to work charging people $$$$$$$.

If you have something constructive to add then please do. As far as I am concerned, the part is installed correctly and functions properly. It is a diaphragm that allows a slight amount of wiggle room for pressure to expand and contract.

Do you really think the diaphragm that is attached to a new a valve cover is made of a different material that materially changes the amount of pressure that builds in the valve cover?

[dworthy]

How many miles?

Very well can be that the oxygen sensor is fouled out from the excess oil getting burned inside the cat.

Also 100k is the factory recommend replacement for the wide band oxygen sensors, so if you are past I would see about replacing them for maintenance reasons.

[Midyetta]

Well I replaced both o2 sensors for bank 2 in the past month with new Bosch sensors. My live data shows they are working ( as well as I can read it)

[White94RX]

I got on this forum to ask for help, not get smart a$$ replies. You have not checked my car. The air leak is gone. The valve cover is not leaking and the code does not specifically indicate that that is the issue. Go back to work charging people $$$$$$$.

If you have something constructive to add then please do. As far as I am concerned, the part is installed correctly and functions properly. It is a diaphragm that allows a slight amount of wiggle room for pressure to expand and contract.

Do you really think the diaphragm that is attached to a new a valve cover is made of a different material that materially changes the amount of pressure that builds in the valve cover?

You're on a forum asking for help. I gave my advice. If that repair actually worked properly, then everyone would be doing it. I have heard numerous stories of it NOT working, having the EXACT same issue you have. In fact, I have fixed many customer vehicles that have done that repair themselves, and it didn't fix their check engine light. But good luck. Proceed with you car as you wish.

[Midyetta]

You're on a forum asking for help. I gave my advice. If that repair actually worked properly, then everyone would be doing it. I have heard numerous stories of it NOT working, having the EXACT same issue you have. In fact, I have fixed many customer vehicles that have done that repair themselves, and it didn't fix their check engine light. But good luck. Proceed with you car as you wish.

My car is not like the other stories I have seen. My car is asymptomatic. No issues with idle or stalling. No whistling.

I see where people botched the job pretty bad by breaking all the tabs. I have read where one fella said he ultimately had his ECU reset (not sure what that did) to correct the light. I don't see on videos where it was tested afterwards.

I was looking for actual diagnostic help with this forum. I'm not particularly interested in replacing stuff just because someone says something 'is trash'..I read that a few things cause a P2098 code.. bad MAFs, failing cats, vacuum leaks, bad sensors, etc.

I know it is difficult to diagnose something and I wish I had the time and money to blow on whims, but I would rather follow a process where I logically troubleshoot something to determine my next action.

If you could tell me how I could determine that the the part is, in fact, trash then please do. What values should the air pressure be would be a logically way to determine, but I am no BMW master tech.

I hear stories too. Like the played out story of guy taking his car to a dealership and spending a ton of money with no results. Change my mind.

[MIKYZZ4]

All I'm going to say is that BMW Genuine Parts definitely do not appreciate being MacGyver'ed.
I'll answer your question from post#1-Replace valve cover with OE part, preferably from FCPEuro.com.
Why you may ask?
To take advantage of Lifetime Warranty with Free Shipping, Something that your local dealer does not offer.

[White94RX]

So did you ever replace your valve cover? Or fix something else? Or still staring at the check engine light?

[Midyetta]

so I did finally get that light to go away. What finally did it was I downloaded ISTA and reset all my adaptions. But no I did not replace that valve cover.