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Is this how Positive Crankcase Ventilation works on the Z22SE?

Discussion in 'Engine Queries' started by Berto, September 28, 2016.

  1. Great info above guys :)

    I'm interested in blanking off the EGR and bypassing the pre-throttle breather hose to stop the throttle body gunking up.

    If I did the EGR blank (keeping it connected electrically) would it be okay to connect a hose from the cam cover to the EGR pipework? Obviously cut it back then slide the hose over the pipe, and blank off the hole on the head.

    Editing to add:

    The idea would be to use the post TB inlet from the EGR as the direction of flow for the cam cover venting, as opposed to passing it over the throttle body.
    #41 csd_19, November 22, 2016
    Last edited: November 23, 2016
  2. Just got round to doing this today Berto (dont laugh changing my lifters has been on my to do list for over two years lol) Anyway the internal diametre was 2.5mm. Hope that hellps. BTW how is your modded PCV system working??
  3. Apologies for the delay.

    Thanks for the info Patricks. [​IMG]

    Like a charm, rev-happier engine and much lower oil consumption.

    I'm currently figuring out how to install a couple of catch cans.
  4. :):)
    That's good to hear Berto :). Unfortunately my oil consumption stayed the same after cleaning the PCV port. So then working on the assumption that my compression rings were fouled and causing high oil consumption i put carb cleaner down the spark plug holes overnight and drained the oil - followed by fresh oil. Interestingly the carb cleaner didnt drain in cylinder two and i had to vacuum it out. No affect tho - oil consumption remains stubbornly high (approx 6-8L/1000km).

    So question.....what is your oil consumption now and what was it before?? And can u give me a bit more detail in how to do the mod. Specifically how do you connect the pipe to the egr outlet? From the pics it looks like the pipe is threaded into the egr outlet but how???. Also what variable valve did u use near the rocker cover and where do i get one?
  5. About 1000 km to drop from max to min on the oil dipstick before, then about 3000 km after the mod.

    Drilled a hole thru the blanking plate, screwed elbow in hole, screwed 3.5mm fitting to elbow, inserted hose from cam cover into fitting:

    a9_t.imgbox.com_2MRqhY4D. . a3_t.imgbox.com_tqXjmTnP.

    Or you can just insert the hose from cam cover into some intake manifold nipple (after removing its cap):


    It was a Hyundai PCV valve but after some testing it showed to be too restrictive and the car run worse with it, so I removed it and have been running without any PCV valve since.
    • Funny Funny x 1
  6. Wish my Haynes manual was as clear as that Berto. Think ill try the second method its easier. :)
  7. ^ If the internal diameter (bore) is 3.5mm I think you'll be OK, that's the size that works best on my Z22SE.
  8. cheers Berto will let u know how i get on. My car is standard apart from panel filter, vec c diesel intake pipe (before filter) and ported throttle body.
  9. Thanks for the information. Have also done a compression test and it was all arranged on all 4 cylinders 12bar.
    I have done also a Cliff by-pass. Unfortunately, by-pass mod did not help me to reduce oil consumption.
    My oil consumption is unfortunately 1 liter at 500KM (310mil). My engine block has now run 240,000KM. But the engine continues to be great.
    It is only true that oil consumption is so high. So far, the car is without a problem by the APK inspection (annual inspection).
  10. Interesting videos on the subject of oil consumption. The guy addresses M52TU & M54 bimmers, that come OEM with a "Cyclone" air/oil separator with return to oil pan, which as it comes doesn't seem to draw much vacuum from the crankcase.

    After discarding the "Cyclone" gadget and implementing a straightforward line from cam cover to intake manifold, with the adequate PCV valve in between, his engine draws more vacuum from the crankcase => oil control rings work better => and his oil consumption drops dramatically:

    ^ To his surprise he finds that the OEM "Cyclone" artifact wasn't pulling any vacuum at all from the crankcase @ warm idle. After the mod he's getting 18" Hg of intake manifold vacuum @ warm idle, which is a bit on the low side (probably courtesy of the leaky crappy cheapo catch can), but within reason and miles better.

    I'm getting 19" Hg of intake manifold vacuum @ warm idle on my Z22SE after the 3.5mm Ø by-pass line (without PCV valve or catch can).
  11. Interesting vid. Cant wait till i see what it does to my oil consumption. Hey Berto i have the plastic cam cover what type/size of drill bit should i use? Have the 3.5mm barb.
  12. Ideally you first use a drill of smaller diameter than the fitting's threaded end, then a tap with the correct size and thread pitch for the fitting. Like this:

    ^ Notice the lots of aluminium shavings, you don't want any of those remaining inside your cam cover baffle, take measures to prevent it. I pressed a piece of rag up the passage above the level of the drilling point, then had a vacuum cleaner running right under the passage while I was drilling to get rid of flying shavings.

    For those interested here's an epic thread on the subject. Pay special attention to what "O2Pilot" has to say, he's on top of it: (BMW M54) Oil consumption after CCV replacement
    #53 Berto, June 29, 2017
    Last edited: June 29, 2017
  13. ^ Missed this. That comes from the Z22YH, yes? I wonder if detaching and reattaching the baffling might be easier on these plastic cam covers than on the metal ones like mine?

    Just in case, while drilling through plastic take care not to melt it around the hole, keep the drill at low rotating speeds and make frequent pauses to allow the plastic to cool.
  14. Berto the later z22se came fitted with plastic cam cover and thats what my z22se has. Thanks for the tip about drilling speed. What type of drill bit do u recommend and size for the 3.5m barb. Didnt realise i had to take the baffling off - thought i was just drilling a hole??
    #55 patricks, June 30, 2017
    Last edited: June 30, 2017
  15. Sorry about the confusion Patricks, no you don't need to take the baffling off for the by-pass.

    I was just wondering for other reasons: The OEM passage for the pre-throttle breather hose is too narrow on the internal side, narrower than what the external fitting suggests ...

    a9_t.imgbox.com_0L4eliUu. . . a0_t.imgbox.com_IbPA9ngv.

    ... and I'd like to enhance the flow by opening it up or by adding a second pre-throttle passage and hose. And most def I'd need to detach the baffling to be able to do that.

    For drilling on thermoplastic I'd use dull bits better than sharp ones. I'd first start with a thin bit, say 2mm or so, then use proggressively thicker bits until a last one slightly thinner than the fitting's threaded side. Then the tap.

    Remember that even thermoplastic may melt under excessive heat, drill @ slow rotational speeds to minimise heat and do frequent pauses to allow for cooling down.

    More great info on the subject: Blow-by and Breather Systems


    ^ Notice how, paradoxically, blow-by volume is higher at lower engine loads (less throttle pedal).


    ^ Why high mileage engines with worn/gunked up rings need extra crankcase evacuation.
    #56 Berto, June 30, 2017
    Last edited: June 30, 2017
  16. My oil consumption is shown as 'low oil' on info display after about 800-900 miles from being full, as the wife reset the mileage counter :facepalm: is this ok? I just don't get why there's all this catch can and pcv business. Should i fit a catch can? Or try the bypass kit described.

    By the way, there is some incredibly useful information here and you guys have some serious knowledge!

    I'm just not sure what to do guys
  17. According to the manual, an oil consumption of up to 0.6 litres per 1000 km is considered normal (by GM at least). That's 1250 km/775 miles from max to min on the oil dipstick (0.75 litres after field remedy 1620).

    At 800~900 miles from max to min you're above the limit, so I wouldn't scratch until it itches.

    BTW what's the mileage on your Z22SE Richard?
  18. Berto you are not going to beleive this or perhaps u can:(. Ive just realised ive been driving WITHOUT the oil filler cap on for the last 800km :censored::censored::censored:. I suppose this would be the utmost form of crankcase ventilation?? No?? Fortunately there is only minimal oil splash happening. Probably lost about 100ml of oil venting thru the opening. Engine feels nicer without the oil cap which i had attributed to the steam cleaning i had done - so i suppose crankcase ventllation is worthwhile. Unfortunately no effect on oil consumption:( Given this observation what size barb should i go for?? Also if i use the nipple on the intake manifold what size hose goes into that??
  19. Ha ha don't worry Patricks that happens in the best of families :D . Save for the Exxon Valdez effect under the bonnet no harm was done if oil level never dropped below the minimum. In fact the Z22SE's cam cover has a nice baffle strategically positioned right under the oil cap that limits spillage in this condition.


    ^ Dead giveaway of excessive crankcase presure from high blow-by ratio. Without the oil cap that presure is relieved thru the large filler hole.

    I'd go for ~3.5 mm internal diameter fittings and hose. If after testing that proved to be too much, you could always restrict it down easily. But you can't enlarge 2 mm Ø fitiings if after testing they don't provide enough flow.

    Honestly I don't know, my engine and me ain't so familiar thus far and I haven't touched her nipples yet. :smuggrin:
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