S55 PCV 'SQUEAL' - Easy Fix (so you don't have to replace the entire valve cover)

[slaughter.mode]

So, today I just got the squeal and I'm at around 93K. I heard it in the drive through---it was faint but then when I pulled into the garage and popped the hood, I heard this (YouTube Video Clip). I pulled the oil filler cap and heard the hiss and the squeal went away so I'm going to pin it on the PCV. Obviously the only solid remedy known thus far is to replace the valve cover.

There's no positive feedback that I could find but I'm hoping the PCV repair kits on Amazon or E-Bay work OR maybe just the Vargas crankcase breather.

Update 9/18/2021 - Attempting the use of the Vargas Billet Crankcase Breather as a solution:

I received and tried installing the Vargas Turbo Billet Crankcase Breather which is claimed to work for, and I quote, "for ALL BMW applications that use the two-prong oil tab style oil fill caps" but it does NOT fit. I can't even get it to sit in the oil fill port without destroying the valve cover. It also isn't designed nearly as well as the oil cap and has no seal or gasket of any kind. It's just a metal unit with two metal prongs so I am confident it is also susceptible to oil leaking. Maybe this is for a track car but for a daily driver like mine? No way. I will try to send it back otherwise I just wasted $100 hopefully for all of us. More info here.

Update 9/19/2021 - Leveraging a PCV Repair Kit from Amazon/E-Bay to Remedy the Issue:

I have tried the following PCV Repair Kits from Amazon (similar to anything else you can find on the web) and I can confirm that none of them work:

Bapmic 11127570292 Engine Cylinder Head Valve Cover for BMW E82 E90 E91 F10 X1 X3 F25 X5 E70 F15

Cylinder Head Valve Cover PCV Repair Kit Compatible For 2015-2020 BMW M3 M4 S55 3.0L Engine

Update 9/22/2021 - Modifying a PCV Repair Cap and Turning it into a Breather:

FIXED! (500+ miles driven. Cold, warm, & hot starts. Smooth idle.) Check it out here.

So I read through Mishimoto's technical write up on Blow-by and then watched an extremely informative webinar by High Performance Academy called, "Is your Engine Damaged? | Blow-By & Engine Breathers [GOLD WEBINAR LESSON]" and put together that the factory PCV is simply not sufficient for my build. Sure, it worked fine for me running Stage 1 for about 70K miles (500hp) but now that I'm in the 700 whp range, the factory components are showing their limitations and rightfully so. What I gathered from reading and watching is that I can essentially convert the PCV into a breather and it should support my high horsepower build exponentially better than that stock design. This could explain why my vehicle is still running perfectly. I believe the driving factor from this is the fact that the velocity of the blow-by gasses are increased quite significantly when you increase power, even at idle. So, tl;dr - I ended up drilling a series of tiny holes to a gutted PCV repair cap and all is running very well so far. (see this post)

Update 8/17/2023 - Soap has found a new PCV kit that may trump this fix as it's a direct replacement for the S55 (finally, right?). So far the result is that it works. This is the first person to use it so will need more data. Here's a link to the post in this thread with the information.

[rmanm4]

I've done it on a N55 and it worked great!

Take your time cutting it out and it will work fine.

[slaughter.mode]

Originally Posted by rmanm4

I've done it on a N55 and it worked great!

Take your time cutting it out and it will work fine.

Gives me hope, thank you. I saw a video of a guy just using cutters to snip a corner without all the hacking and sawing. Took 10 seconds for him to get it off with a cut and a screwdriver.

[fiveohwblow]

Nothing to lose given its that or the whole damn thing. I have had to replace mine on the n55 and n51 due to this. Hated it.

[slaughter.mode]

Originally Posted by fiveohwblow

Nothing to lose given its that or the whole damn thing. I have had to replace mine on the n55 and n51 due to this. Hated it.

You're not wrong...it's just one of those things that give BMW repairs a bad rap.

[slaughter.mode]

I ordered up the last of the PCV caps. Will report back when I install it next week. Fingers crossed.

[joooiiiiii]

Originally Posted by nv_f82

I ordered up the last of the PCV caps. Will report back when I install it next week. Fingers crossed.

goodluck.

[rmanm4]

Originally Posted by nv_f82

Gives me hope, thank you. I saw a video of a guy just using cutters to snip a corner without all the hacking and sawing. Took 10 seconds for him to get it off with a cut and a screwdriver.

Keep watching as many videos then attack it with the tools you have. I used a Dremel to do the cross cut and then used my hand and a flat screen driver as a chisel to get the cap off. You just need to be careful with the cut as if you go too deep you will cut into the VC and then you fucked! It's not hard, take your time and you will be fine!

[slaughter.mode]

I wonder if this would be a good addition other than an eyesore for my engine bay.

https://vargasturbo.com/product/vtt-...case-breather/

[slaughter.mode]

Originally Posted by rmanm4

Keep watching as many videos then attack it with the tools you have. I used a Dremel to do the cross cut and then used my hand and a flat screen driver as a chisel to get the cap off. You just need to be careful with the cut as if you go too deep you will cut into the VC and then you fucked! It's not hard, take your time and you will be fine!

Yeah I'll just wolverine the middle of it with my dremel then peel it back until it detaches from the lip. What did you use to re-seal it? High temp silicone? I'm guessing I'll want something strong enough to keep it in place but not too strong so that it's impossible to remove. The plastic cover that sits over it I'm assuming is enough to keep the thing collapsed in place and prevent the spring from popping it out.

[rmanm4]

Originally Posted by nv_f82

Yeah I'll just wolverine the middle of it with my dremel then peel it back until it detaches from the lip. What did you use to re-seal it? High temp silicone? I'm guessing I'll want something strong enough to keep it in place but not too strong so that it's impossible to remove. The plastic cover that sits over it I'm assuming is enough to keep the thing collapsed in place and prevent the spring from popping it out.

I used JB weld. Don't use anything else!

[slaughter.mode]

Indeed it was the PCV membrane:

[rmanm4]

Mine on the N55 fell apart it was so brittle! They dry out due to the heat cycles and form cracks and holes!

On the N20 engine its a module and easy to replace but on the N55 and S55 its built into the VC making it a expensive job!

[slaughter.mode]

Originally Posted by rmanm4

Mine on the N55 fell apart it was so brittle! They dry out due to the heat cycles and form cracks and holes!

On the N20 engine its a module and easy to replace but on the N55 and S55 its built into the VC making it a expensive job!

Yeah I ran into another challenge-the cap itself. I don't know if it's age or the high temperature area I live in but it was seemingly fused to the valve cover. The traditional cross cut or clip & snip methods to get it off did NOT work for me. It was a hack job. I'm thoroughly disappointed in this design considering other BMW engines have a replaceable cap...

...but then I got to thinking. This is a common issue. I'm going to fabricate a better solution than this generic cap I found on Amazon...which is now running late.

My initial thought is to design a thin walled aluminum sleeve with notches built in that I can press onto where the factory cap was removed and then leverage a BMW PCV cap which has the clips for easy removal and replacement. I don't see why this wouldn't work so long as the spring and membrane work as intended. Furthermore the plastic shroud should assist in keeping the cap on and I'll probably place a foam pad with 3M adhesive on the bottom of the shroud to assist in tension on the cap.

[rmanm4]

Originally Posted by nv_f82

Yeah I ran into another challenge-the cap itself. I don't know if it's age or the high temperature area I live in but it was seemingly fused to the valve cover. The traditional cross cut or clip & snip methods to get it off did NOT work for me. It was a hack job. I'm thoroughly disappointed in this design considering other BMW engines have a replaceable cap...

...but then I got to thinking. This is a common issue. I'm going to fabricate a better solution than this generic cap I found on Amazon...which is now running late.

My initial thought is to design a thin walled aluminum sleeve with notches built in that I can press onto where the factory cap was removed and then leverage a BMW PCV cap which has the clips for easy removal and replacement. I don't see why this wouldn't work so long as the spring and membrane work as intended. Furthermore the plastic shroud should assist in keeping the cap on and I'll probably place a foam pad with 3M adhesive on the bottom of the shroud to assist in tension on the cap.

Good idea, let us know how it works out. I still dont understand why there is no aftermarket VC that has a modular PCV! I guess it doesnt need to be replace frequently enough!

[slaughter.mode]

Originally Posted by rmanm4

Good idea, let us know how it works out. I still dont understand why there is no aftermarket VC that has a modular PCV!

Well there's the Vargas one which seemingly removes it all together and instead offers a check valve/breather with a ball in it that sucks shut or lifts open depending on vacuum/venting needs...but nobody has one that I know of or has installed one...that I know of. I've been asking for some results but nada.

[rmanm4]

Originally Posted by nv_f82

Well there's the Vargas one which seemingly removes it all together and instead offers a check valve/breather with a ball in it that sucks shut or lifts open depending on vacuum/venting needs...but nobody has one that I know of or has installed one...that I know of. I've been asking for some results but nada.

Ya there is no long term data that shows it holds the correct amount of pressure.

[slaughter.mode]

Originally Posted by rmanm4

Ya there is no long term data that shows it holds the correct amount of pressure.

I e-mailed Vargas, we'll see.

[slaughter.mode]

Their response:

"It removeds the factory PCV, keeps the low side built into the VC, and move the high side to VTA, and you can run your catch can with it ou ours.

No effect on idle quality, and as long as you run the can off the port near the oil cap. No oiling issues"

[rmanm4]

Originally Posted by nv_f82

Their response:

"It removeds the factory PCV, keeps the low side built into the VC, and move the high side to VTA, and you can run your catch can with it ou ours.

No effect on idle quality, and as long as you run the can off the port near the oil cap. No oiling issues"

Saying all the right things doesn't mean it's true. Last thing you want is your rear main seal blowing out overtime and costing you a arm and a leg to replace! Idle is not the concern, it's the RMS!

[slaughter.mode]

Originally Posted by rmanm4

Saying all the right things doesn't mean it's true. Last thing you want is your rear main seal blowing out overtime and costing you a arm and a leg to replace! Idle is not the concern, it's the RMS!

I can see it providing enough venting to prevent that but I can't help but be concerned with a vent to atmosphere design that's just always open. How couldn't that cause a bad idle? 🤔 I don't think I'll bite either way, my car is a daily driver and this product seems more of a track-oriented side grade.

…Plus my badass carbon fiber m performance engine cover turning into a wall ornament feels wrong.

I'll see what I can fabricate and post back.

[Tangent]

I had the same PCV failure recently. I was on the fence about getting the cap replacement alone because of mixed results but I figured I might as well try. Unfortunately the post office lost the package. I contacted the seller and they offered to ship me a new one which I happily accepted but unfortunately it never actually shipped (waited a month). It just added up to a bad gut feeling so I'm actually expecting a FedEx package with a complete valve cover today. I'm planning on keeping this car long term so I got it through FCP Euro so my next one in another ~80k miles will be free.