My car is a 2012 F30 335i (N55), it has about 99,300 miles.
After 7-8 years, the PCV/CCV on these cars will usually fail.
The failure is due to the thin orange plastic membrane
under the PCV/CCV cap, which is at the top of the Engine Valves Cover.
PCV = Pressure Crankcase Valve
CCV = Crank Case Valve
The symptom to this failure is usually either:
- hissing noise at the top of the engine due to the air being sucked into
- idling of the engine is irregular, and sometimes engine would shut down, similar to as if you had left the oil cap slightly loose or not fully tighten...
The purpose of this membrane is to maintain a sealed vacuum within the engine, and yet to allow the pressure to change without damaging engine components.
A crack membrane (failure over time) compromises the vacuum of the engine, and thus the engine will have difficulty working.
The normal way to fix this is to have the entire Engine Valves Cover replaced, which can cost anywhere between $170 to excess of $500 depending on which brand, official or knock-off you buy, and labor at the dealership can vary between 2hours up to 5hours ($200 to excess of $500).
For $15, you can fix it yourself, this job is only 5 to 10 mins long, but if you are new to this, it might take at least 30 mins if you go real slow and being careful about it.
This is considered a Hack, for those of us who cannot or do not want to pay much money to fix our car.
If you are able to afford $500 or $1000 just to replace this particular part, be my guest.
Here
I am showing this for information only.
Proceed at your own risk and peril, please take safety precautions.
I am NOT responsible, nor liable for any personal safety, product failure arising from you attempting this job yourself.
Do not blame me for your mistakes and errors, you are fully responsible of your actions.
Common tool needed:
Chisel
Hammer
seesaw or drumel
cleaning towel
sealing silicon
The new replacement Cap can be found on Amazon: "
Cheriezing 11127570292 Engine Valve Cover for BMW X1 X3 X5 X6 xDrive 535i 335i 435i"
Based on my observation:
You do need much glue to fix it, at least with the N55.
You dont need to over-glue this replacement cap... just enough for it to hold.
1) you start by cutting one of the corner of cap at the top, without going too deep.... you should stop as soon as you see the orange membrane:
It's plastic, so this is going to go real fast...
This is what you are trying to do: cut as carefully as possible one side of the cap so that it can be popped up/open...
The PCV/CCP Cap is essentially snapped/clipped to the top of the engine cover, contrarily to what most people thing... and even if it was glue, it was done very very lightly...
The reason is, under normal operation and load, the CAP is Sucked tight... the pressure is negative: meaning that the vacuum from the engine maintains the cap in place by suction.
2) When you start seeing the orange membrane, proceed very carefully, so that you do not damage the Engine Cover:
3) You want to cut the cap and achieve this:
Once you arrive at this stage, you should take a thin phillips screw driver to pry this cap open as carefully as possible:
4) You can either pry the side of the cap or if there is a gap at the top going above the orange seal as i did here:
a bit savage:
5) Clean Snap up!
The reason there is a spring under the cap is because the spring prevents the orange plastic membrane from collapsing due to the engine vacuum suction...
The membrane serves as a soft sealing cap that can allow pressure differential, and the black plastic cap is to protect that soft membrane from the elements.
6) Analysis of the damage and failure:
The way you open and remove this cap from the Engine Valves Cover is destructive, you will not be able to re-use it because it already has failed in the first place...
In this photo you will see the damage i did to the cap, but also the cracks on the orange membrane that could not have been induced by me or during the removal... The orange membrane already failed and cracked prior to our removal.
I destroyed the side of the black cap, but the orange membrane shown here is clearly cracked prior to my removal... due to constant suction over 7 years... (hold you jokes guys)
7) CLean up the blow-by engine oil that has been caked/baked here:
8) The replacement part doesn't look the same, but it fits in perfectly:
This is how it would fit in, as oriented:
9) you dont have to clean, but it is the right thing to do at this point:
10) from this perspective, you can see the small little damage i did to the engine cover when i was trying to cut the PCV cap:
Try to avoid cutting the Engine Cover/Housing for the PCV/CCV Cap like i did:
11) Once all cleaned up, do not forget to put back the spring:
12) Notice the light gray line around the outside wall of the "cylinder":
That's the very little amount of "glue" originally used to seal it...
so that's how little we are going to try to use:
13) you can just smear just a little bit of plumbing/silicon gasket/sealer around the side of the cap, to prevent tiny air leak into the engine...
DO NOT PUT glue or sealant on the top surface, only on the side outside wall, do not put inside the cap
The reason you dont want to use too much of is: so that you can be able to do this job about 70,000 miles later down the road...:
if you use superglue, or too much sealant, then it will be impossible for you to remove the cap again...
14) Snap or push the Cap down in the correct orientation.
Hold it down for a couple of minutes so that the cap doesn't spring back out, help the glue or sealant cure and set before letting go
IMPORTANT: There is a tiny plastic cap at the top of the PCV cap you are replacing, you need to remove it and put it on the new replacement PCV Cap!
Good Luck... and remember, i am not responsible for your screw ups.
You can find a lot of youtube videos on this topic, but most of them are showing how to do this the long tedious way.
For the N55, it is very simple for 2 reasons:
1) The PCV/CCV location is right on the top, ease of access, but Depending on your engine type, it can be in weird places where you have to remove quite a bit of things and potentially even the Engine Valves Cover.
2) There is no retaining tabs/clips to break off, as could be seen on much older engine model/types. On the N55, the PCV is flat at the top, so the cap doesn't risk to fall off. On other engine, it might be off to the side of the engine, at an angled surface, which would require the use of glue...
I have to give credit where credit is due:
Thanks mate for this tip!
