JantzenRX-8

iTrader: (9)

Ok, well no one answered my question. So this is what i came up with.

I assumed, after nearly conclusive research, that the line coming from the back side of the manifold was from the PCV valve. I pulled off the end that was plugged into the intake and there was a little oil residue so i figured i was right.

Let me know if this makes sense. I couldn't think of a way to get both vents to the catch can and not have them returned to the intake so i connected them to a tee adapter, ran them to the catch can and then put a breather filter on the other side of the catch can.

P.S. this catch can is really big and i searched long and hard for this little nook in my engine bay... Aggravating

Jon316G

iTrader: (1)

I'm confused.....
If you installed a catch-can with a breather, why did you run it back to the intake.
With a breather on the catch-can, you should just cap the fitting on the intake.

Not only that but by inserting a T-fitting where you did, you kinda defeated the purpose of the catch-can (if I'm looking at that pic correctly).
Oil still has a direct path to the intake.
The catch-can is meant to go between the oil filler neck and the intake.

JantzenRX-8

iTrader: (9)

You're looking at the pic wrong.

Both tubes flow into the catch can. None return to the intake.

See my awesome paint abilities...

In the first pic the red "stock hose" is what i've seen most people have who install catch cans. The previous owner of my car clearly had the milky dipstick TSB re-routing done which i mapped out in yellow.

Vyndictive

iTrader: (28)

Jantzen: Jon and I talked about your first post and couldn't really understand what you meant with the "reach around" intake line.

Looking at your set-up, its flawed. The intake is under vaccume from the engine... so Jon is right, at your "T" connection, IF any oil vapor is blowing off from the oil filler neck, it'll be sucked into the intake hose return line because of the vaccume... Nothing will enter the catch.

Jon, chime in whenever.

To fix this, cap the intake port and remove the hose running back to the intake. If you do this, your set-up will be good. Oil will blow by the filler neck into the hose into the catch can. The breather allows filter air (not oily air) to escape and the oil will coat the inside of the catch can instead of inside your intake.

Vyndictive

iTrader: (28)

Ok... looking at your new pics with the paint hose routes it looks fine... But I still don't know why you ran the hose from the front of the intake to the back of the intake?

JantzenRX-8

iTrader: (9)

In which color. Yellow? or Blue?

Vyndictive

iTrader: (28)

I looked at the yellow in the first pic. . .


Alright in the blue.... one hose connects to the filler neck... where exactly does the other hose connect to?

It looks like it connects to the back of the intake. Which would still defeat the purpose.

I could be looking at wrong.

JantzenRX-8

iTrader: (9)

The yellow pic is Mazda's doing. It was really hard for me to imagine them just putting a random hose from the back of the intake to the front of the intake so my thought was that this hose was coming from the PCV valve where the crankcase was venting oil/gas fumes back into the intake to be burned off. When i pulled off the hose there was definitely some type of oil residue which made me think i was right.

http://en.wikipedia.org/wiki/PCV_valve

I read this and thought wouldn't it make sense to run this through the catch can as well rather than re-introducing it back into the intake?

Attached is the best i can do to show the "yellow" hose from above which i am now running to the catch can.

JantzenRX-8

iTrader: (9)

to help further explain

Jon316G

iTrader: (1)

Oh my lord......
I think you are making this way more complicate than it needs to be.
But I am REALLY curious where you routed the hose under the intake manifold extension.
You obvious didn't purchase the updated oil filler neck and extension, so where in the world did you route this?
Here is a pic of my UIM:


Show me where you routed the line from the oil filler neck!

JantzenRX-8

iTrader: (9)

HAHA. I know.

I honestly don't see it in your pic but then again i could not completely see it when i was in there. I'm going to feel like a big doofus if it is just one of those tubes coming out of the bottom side of the UMI but i thought it was much lower and horizontal.

Ok, i'm going to go pop the hood. This is really getting to me.

Jon316G

iTrader: (1)

What I'm worried about is this...
Judging by the pics you've posted, it almost looks like you routed the line to the nipple under the intake manifold that connects to a vacuum chamber for the SSV, Air, and VDI solenoids.
That would be bad!

JantzenRX-8

iTrader: (9)

Ok, it's confirmed it is in no way connected to the UMI. It is attached below the UMI right above the oil line coming to or from (not sure of the flow direction) the oil filter.


Before: Oil filler neck, to a tee, to both maintenance ports on the lower part of the intake manifold.(compliments of Mazda)

Now: Oil filler neck, to a tee, to catch can. (first pic should show this unless you're asking for something different)

Jon316G

iTrader: (1)

OK.... so just to finalize what should be done in your situation....
Run a line from the oil filler neck to a catch-can with a breather installed.
Then capped the fitting on the accordion tube.
Nothing else needs to be done.
Simple as that

JantzenRX-8

iTrader: (9)

You're probably right. I think i'm going to re-route it.

Jon316G

iTrader: (1)

Yeah... just keep it simple

JantzenRX-8

iTrader: (9)

OK, done.

Thanks.

JantzenRX-8

iTrader: (9)

Ok, i just actually re-routed it. Nothing quite like working on your car at 11:45 PM.

After all this i'm still baffled where that line went to before the TSB re-route.

If the oil filler was oringinally plugged into the intake and then the TSB removed the line from the intake and routed it to the maintenance ports -- this makes sense. But when you have some random line come out from depths of your engine bay to plug in where the oil filler line used to plug into that just doesn't make sense! Where was that plugged into before? Why did it need to be moved?

Jon316G

iTrader: (1)

The TSB didn't route the intake (accordion tube) to the maintenance ports.
It went from the oil filler neck to the maintenance ports.
Then a separate line went from the intake accordion tube to the "depths of your engine bay" to the modified oil filler pipe (not at the neck).

Since you don't have the new oil filler pipe assembly, you can't see where that TSB is routing the line within your vehicle (and I don't have a pic of the new assembly).
This is why people with '04 or '05 RX8s either install a catch-can after the oil filler neck and route a line back to the intake, or install a breather onto the catch-can (bypassing the need to route back to the intake) and cap the fitting on the intake's accordion tube.

neXib

I wasn't aware of this. Can I easily see if I have already been stupid and overfilled oil?

Mazurfer

Well.....I'm not sure I understand your question, but your dipstick would tell you this.

Also, if you take look inside your airbox and find it oily, that could be an indication as well.

It's also possible that as you fill the oil(too fast), oil can run down that hose and into the intake............although most probably gets in there from blow back and you have an increased chance of that if you over-fill.

The catch can eliminates this altogether as any blow back or overfill would go into the catch can and not the intake.

If you go to do this, look above at what Jon316G says is the proper way to have it configured.
Line from oil filler neck comes off the intake and goes to catch can. Then, you either put a breather on the other side of the catch can and put a nipple on the intake OR you route the
catch can back to the intake where you took the original hose off.

thawk97

I don't know anything about this until I just read it this morning. I did my own oil change recently and I think I filled the oil too fast because when I went to change the air filter the next day I actually had standing oil in the accordion tube (it was fresh clean oil which is why I think it was because I filled too fast). Either way, this is how I discovered oil could be pushed back into the intake system. So, I am thinking I want to install a catch can.

Question though - why would you ever route the catch can back to the intake system again? I understand putting a breather on it and capping the intake nipple, but I see one of the options to to hook a hose back to that nipple from the oil catch can - doesn't this defeat the purpose of having a catch can? OR, what am I not understanding...

JantzenRX-8

iTrader: (9)

Why don't i have this oil filler pipe assembly? Wouldn't the TSB have included it? What does it look like on the '06's and up?

I can't cap the i tube off the accordian tube because if i did that there would be an open ended hose just flopping around in the engine bay. I had to re-connect hose from "the depths of my engine bay" back to the accordian tube.

Mazurfer

kind of...............but if you routed the hose back, you would still get oil vapors and not the oil(it would stay in the catch can).

I guess some might think that the oil vapors might lubricate the throttle boddy valve on the intake in some small manner?


Sounds like you did fill it too fast. If no catch can.......use a funnel, pour slower....it might help.

thawk97

Yeah, it was cold out and I was during a whole bunch of work so trying to go quickly before I froze to death - I'll pour slower in the future - but now that I know it could be an issue I am trying to decide if I should put a catch can in....

Is there a consensus on whether a breather should be used or a line back to the intake? anybody else got thoughts on this? why would mazda route the oil there in the first place - is there a reason to at least have vapors in there? If I am going to do it, I want to make sure I do it right...