[jnrz78]

HI,

I knew to this forum and seems like there is a lot of deep knowledge here and wondering if anyone can help me out.

I also have some sort of chirping/ringing/whirring noise coming from near the PCV area. The car has now done 50,000KM and it is a 2011 n55 335i model.

I performed a quick test as described for the water test. There wasn't any bubbles at low revs, however, when I hit the throttle, I can see the water being sucked in/out.
Can this also be a dead PCV issue? The noise is really doing my head in!

I have also recently done a full engine oil flush, replacing the oil filter. I have also recently changed the boost solenoid which hasn't resolved the issue.

Any help would be much appreciated..

Here are some videos of the noise from the engine:

https://www.youtube.com/watch?v=KgVW...ature=youtu.be

https://www.youtube.com/watch?v=eND7...ature=youtu.be

ttps://www.youtube.com/watch?v=48om...ature=youtu.be

[tcabill]

Your write up was great. My car was doing this weird boost osilation and on logs the throttle was going up and down kinda like a heartbeat. I'm running MHD map 2+ for E30 but when I flashed back to stock it wasn't as noticable but the logs still showed it, just not as extreem. I did have the squeal from the rear main seal but I didn't know what it was till I stumbled on this post. Got my new valve cover on a few hours ago and she's back. Boost is nice and steady and hitting 20 psi again. Thanks for posting your findings.

[tpmmazo]

Originally Posted by remixsecret

I did this hacked job with the PCV valve replacement part off vanos website. Squeal is still there but less now, but else could be the issue to fully get rid of the howling sound?

What did you end up doing to fix it. I replaced but the squeal is still there.

[gillzj00]

As I have been kind of active on this thread I want to make an update:

The squealing from the rear main came back strong about a year after I noticed it. It would squeal non-stop every time I drove. I replaced the PCV using the write-up provided in earlier posts. The sound went away for a couple months. The sound came back but is more sporadic now. I ordered a new valve cover from FCP Euro and plan on doing the job this weekend. I am hoping a new cover in it's entirety will finally fix this issue semi-permanently.

I will try to update this post a few months from now to confirm/deny that the valve cover (OE) fixed the issue.

[Petr4271]

Here is also video with explanation ,doesn't seems to be that hard to change PCV valve itself.

[Scuttles]

Im getting ready to replace the Valve Cover Gasket on 13 335i n55. 65k miles, probably makes sense to replace the PCV at the same time/as preventative.

Im wondering if it is possible to replace the diaphragm only without cutting the PCV off the top of the valve cover?

And just to be crisp, is this the only part needed?

n55 eBay

THANK YOU!

[vespa]

The diaphragm is sealed inside a compartment so you'd still have to cut it apart and glue the replacement part back on. One big advantage to doing it with the cover off is that you will have a much better chance of keeping the plastic shavings out of the engine.

But it's still quite a hack, quite a bit of added effort, and you risk breaking something on the VC in the process, screwing up the new valve, or getting dirt, plastic, or glue clumps in there along the way. It's even possible that your oil leak is thru a crack in the cover rather than the gasket. It's so much work to remove the valve cover, I'd strongly suggest spending the extra $300 to replace the whole cover. It comes with bolts and gaskets and you know it will work perfectly.

[cyclonexcry]

does is cause boost leak?

[vespa]

No. Crankcase pressure and boost pressure are unrelated.

[rmap3k4mhdac6]

I recently installed the MHD stage 1 on my 2013 135i (N55) and i immediately noticed the rear main seal squeal sound after the flash. I put the stock tune back on and the squeal went away. So I researched everything and found that the squeal is a symptom of PCV problems. I performed the flame test on the PCV valve nipple and verified that the PCV membrane had likely failed. I found it strange that there was no squeal on the stage 0 (stock) tune, but there was loud squealing every time I came off the throttle with stage 1.

My hypothesis is that the change in valve timing from Stage 0 to Stage 1 results in a reduction of positive crankcase pressure. On stage 1 the engine does does not create enough positive crankcase pressure when off throttle to balance the amount of unregulated vacuum being pulled through the broken PCV valve. This extra negative pressure pulls air in through the rear or front main seals and makes the squeal sound off throttle.

So I have replaced the PCV valve yesterday, rather than the whole valve cover, via a 15$ Ensun Amazon replacement and some JB weld. This morning the car ran fine as usual on stage 0. I will test stage 1 after work and report back here about the squealing.

[AX75F92]

Hey guy I could use help.

2011 N55 developed a VC gasket leak around 50K miles. No squealing at this time.

I replaced the whole VC to avoid a future PVC failure. No oil leak, but now I have the squealing noise, only once the engine is fully warm.

Thought it was a defective VC (URO Parts from Rock Auto). Got a replacement. Installed replacement. Same issue.

Can I be overlooking something in my installation that would cause this?

What are the chances of two defective brand new units in a row? Seems odd.

I am about to demand a refund and order a genuine BMW VC.

Anything I should check on?

Car has a BMS oil catch can and JB4.

Thanks!

[Gjohnson7]

Just thought I would drop this video here. I have been trying to figure out my rough idle, seal whistle and new lean code issues, when I came across this video. I just got home and went out to check via the instructions in the video and sure enough I have a pool of oil sitting in this vacuum line. If what is in this video is correct, my valve cover is toast.
Can anyone confirm if this is truly an indication of an internal leak?

[Gjohnson7]

Below is a quick link to a video I just posted to my channel. Anyone that is suffering from a bad PVC/CCV may want to consider cleaning their intake valves with this method or Walnut Blasting. As you can see from this video, I had quite a bit of carbon build up on my N55. Not sure how long the previous owner went with the this Bad PCV system. Also, toward the end of the video I have a quick review of the non-OEM valve cover I picked up on Ebay. It was really good quality.


N55 Intake Valve Cleaning and Replacement Valve Cover

[N55Rocket]

Originally Posted by tcabill

Your write up was great. My car was doing this weird boost osilation and on logs the throttle was going up and down kinda like a heartbeat. I'm running MHD map 2+ for E30 but when I flashed back to stock it wasn't as noticable but the logs still showed it, just not as extreem. I did have the squeal from the rear main seal but I didn't know what it was till I stumbled on this post. Got my new valve cover on a few hours ago and she's back. Boost is nice and steady and hitting 20 psi again. Thanks for posting your findings.

I hate to be that guy that asked a question on a old thread but I also have 2011 BMW 335I N55 E92 Coupe ànd I have most bolt-on performance parts and the MHD tune with full exhaust with catless down pipes. I recently lost almost all of my boost and I did smoke test and nothing with no codes but the PCV on valve cover is bad and leaking and I know that it has something to do with boost but not sure if it would cause a Hugh boost leak. But I see your post stating you did valve cover and your hitting 20psi of boost again, so question is was you down on your boost before your repair and after the repair you was having fun with full boost again.thank you in advance

[540ig5]

thanks.

[N55Rocket]

Originally Posted by tcabill

Your write up was great. My car was doing this weird boost osilation and on logs the throttle was going up and down kinda like a heartbeat. I'm running MHD map 2+ for E30 but when I flashed back to stock it wasn't as noticable but the logs still showed it, just not as extreem. I did have the squeal from the rear main seal but I didn't know what it was till I stumbled on this post. Got my new valve cover on a few hours ago and she's back. Boost is nice and steady and hitting 20 psi again. Thanks for posting your findings.

Wow dude I know this is a old Post but I been replacing everything trying to find out while I been having crazy boost issues and my idle was doing the surging issues also. I knew that the Pcv valve is bad in my valve cover but didn't think that was the issue because I didn't think it would cause a problem with boost

[N55Rocket]

Originally Posted by N55Rocket

Wow dude I know this is a old Post but I been replacing everything trying to find out while I been having crazy boost issues and my idle was doing the surging issues also. I knew that the Pcv valve is bad in my valve cover but didn't think that was the issue because I didn't think it would cause a problem with boost

Sorry forgot to put problem is fixed also with the valve cover replacement

[reevo_red]

awesome job. thanks

[dewana421]

Originally Posted by vespa

The N55 PCV system is permanently integrated/sealed into the valve cover and is generally non-serviceable but an understanding of the function and fault diagnosis may be useful to some so I will attempt to explain .............necessary to reduce evaporative emissions and is one of several tweaks that led to the SULEV rating.

awsome post OP...one question...did you replace the valve cover with a genuine BMW one or after market? if after market how has it been holding up?

[vespa]

Thanks, I used BMW PNPC to find the best price on an OEM cover and have had no problems since. At 110K miles now.

[hardparker]

The easy way to fix the PCV diaphragm in the valve cover:

[nic_m3]

Does this also apply to n52k engines additionally are the hours from the service bulletin what I could expect to be charged?