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Crank Case Vent Installed

5.1K views 45 replies 20 participants last post by  mdogg  
#1 ·
2 days ago I purchased a crank case vent from Auto Zone. The part cost about $8. The installation took about 5 minutes. I used the vac hose coming off of my Fujita CAI to assist with the installation. I cut the hose up so the filter would fit to the vent on the engine head. I also used the hose to place a metal slug into to keep the intake hole plugged. I used the hose to plug it so I could use a wide object that would never get sucked into the intake.

I repeated the steps that lead to my car smoking:

1. Get off work at 5:00 PM (Florida heat and humidity are at 90 degrees and 75%, respectively)
2. Start car with A/C on
3. Idle for a few minutes
(smoke starts to eek out of rear, visible in mirrors)
4. Blip throttle
(smoke is embarrassing upon blipping the throttle)
5. Drive away, experiencing smoke for the next 2 or 3 traffic lights.

Well, for the past two days since I've installed the crank case vent, there has been zero smoke. The only smoke was after I installed the vent and then idled the car for 5 minutes. It produced a minimal amount for about 2 minutes and stopped.

I'm a happy customer, so far. I'll keep everyone updated.

It should be noted that the vacuum hose I cut up had a small amount of oil/fuel residue in it. It clearly had that smell, too.


Misc. info that may be needed:

Mods: Fujita CAI, TXS race pipe, MBC @ 17psi, ATP fuel-cut defender, crushed 1G DSM BOV and AWR 70dm MM.
Car has 8k miles on it as of today.
Early build
Mobil 1 10w-30 changed at 5.5k miles
OEM Mazda oil filter

Pics:

Image

Image
 
#4 ·
woa woa woa, don't take all the credit...I actually had this done before you :p Also I was going to say that either Autozone or Advanced Auto Parts actually sells in their little help section large end caps that fit perfectly over the little pipe on the fujita intake...thats how my setup was on my fujita until I sold it on here when mazda freaked out about my modifications...
 
#5 ·
Definitely not taking all the credit.


I did get it from someone mentioning it on this forum and thought to myself, "that's probably the solution!"


I felt that it definitely deserves its own thread. Especially with people getting their turbos replaced!


Also, how's it coming along for you?
 
#6 ·
When I had mine setup that way it never smoked at all...I truely believe its the solution to most everyones smoking problems...there may be a handful that truely have bad turbo seals, but I think most of them just need to go this route and see what happens...
 
#7 ·
I know on older cars, that have bad valve seals and throw oil all over into their valve covers that the vent can allow oil into the intake, but, I am blown away that on basically a new car this is happening?!?! Wow...

I mean, yes, its known to occur because of the vent, but NOT on a new car! Hrm, wierd...
 
#9 ·
As for the turbos, maybe a restrictor inline for the oil feed would help.

If people are blowing their seals, it could be to too much oil pressure build up?
 
#10 ·
Haha, I did this when I installed the ATP kit in January because I could not find any good way to connect a hose to the inlet pipe. I had always wondered why people insisted on getting the oil catch cans when you can just solve the whole problem with a small filter.
 
#11 ·
Seems like a fix for the symptom, but if mine did that I would want to find the root cause. Sounds like a huge blow-by problem. Not a good thing if the rings are giving up the ghost this early. It's got to be killing the cats as well. EPA should be all over this.
 
#12 ·
Now instead of doing this...is it possible to install an inline filter in that hose? I had this done on my Probe as preventative maintance, but maybe I'll look into this route for the Speed now. This is not my engine bay and kinda hard to see...but you can get an idea on what I mean:
Image

The filter itself is right next to the CarDomain tag along the bottom.


Ăźill
 
#13 ·
Now instead of doing this...is it possible to install an inline filter in that hose? I had this done on my Probe as preventative maintance, but maybe I'll look into this route for the Speed now. This is not my engine bay and kinda hard to see...but you can get an idea on what I mean:
Image

The filter itself is right next to the CarDomain tag along the bottom.
Ăźill[/b]
I installed an inline fuel filter that I found at Pepboys on my Talon. I had a line coming off the vent, the filter, and then a line coming off the filter pointing down in the engine bay (didn't have an inlet on my intake pipe). Otherwise, if you just put a filter on, won't it spew oil around the engine bay?
 
#14 ·
The filter would be inline...meaning keeping the hose in place, just cutting it and putting the filter in there while keeping it connected to both the CAI and the engine. I have some extra hose, I am going to give this a try and see if I can make some more smoke.


Ăźill
 
#15 ·
The filter would be inline...meaning keeping the hose in place, just cutting it and putting the filter in there while keeping it connected to both the CAI and the engine. I have some extra hose, I am going to give this a try and see if I can make some more smoke.
Ăźill[/b]
Oh sorry, I meant to say to the original poster about oil spray with the filter connected to the vent w/o any extra hose.
 
#16 ·
sweet so all of you have no concept of why mazda and every other manufacture use positive preasure in the valave cover and crank case?
 
#17 ·
sweet so all of you have no concept of why mazda and every other manufacture use positive preasure in the valave cover and crank case?[/b]

http://www.autoshop101.com/forms/h63.pdf

Here is a decent explanation on Toyota's system. Mostly to control normal blow-by gases. It also helps keep the oil clean of blow-by gases and moisture, which is a known generator of sludge. The odd thing here is that, normally at idle, there really should not be much going through that system. There is some other problem here, not a good idea to disable that system.

If it was me, I would be taking some video and sending it to Mazda. They are obligated to fix this, of course the intake would need to be stock or MS stuff.
 
#18 ·
two possible conclusions

1) oem vent path is restrictive and/or blow by is high, causes back pressure in crank, and leak at tubo seals (filter stays clean). PCV should help prevent this.

2) high blow by with oil vapor (high oil level?), and mod prevents oil from reaching intake pipe. catch can would work too. (oily filter)
 
#19 ·
two possible conclusions

1) oem vent path is restrictive and/or blow by is high, causes back pressure in crank, and leak at tubo seals (filter stays clean). PCV should help prevent this.

2) high blow by with oil vapor (high oil level?), and mod prevents oil from reaching intake pipe. catch can would work too. (oily filter)[/b]
Or there is some other problem that needs more than band-aid attention.
 
#20 ·
everyone that has installed a catch can has never found any oil in them.

i really am starting to beleive that the oil smoke is coming from ring failure. think about it 9.5-1 compression with over 16 psi of boost on top of that most of the complaners are the ones that race there cars so you can factor in alot of time over 5k.

i think alot of you guys that are haveing smoke need to first do a compression test and then do a leak down test if thats fine it still doesnt rule out ring flex but its a good start towards finding the real problem
 
#22 ·
If what you say is true then this car would be running low on oil all the time.[/b]
not really, it doeant take much oil to make smoke

are many of you haveing to add oil? because i am and i dont drive my speed6 hard but i dont drive it daily either
 
#23 ·
Well I have felt bad blow by before and my car didn't do it while idling. Now as far as under hard driving goes the people with catch cans should be seeing oil should they not if blow by is occurring?
 
#25 ·
Keep an eye on that filter, I have one also and it blows off all the time, no matter how tight I wrench it down. Must be a lot of crankcase pressure being built up.
 
#26 ·
Keep an eye on that filter, I have one also and it blows off all the time, no matter how tight I wrench it down. Must be a lot of crankcase pressure being built up.[/b]
if you have that much preasure in your valve cover then you have bad valve seals gandalf