Catch Can install question
 

so i was reading the DIY thread for catch cans since i got a greddy one.

when i got to the step about the hoses it said to remove the hose that connects the oil and the intake.

the problem is.. my car doesn't have 1 hose connecting the intake to the oil. they each have separate hoses leading somewhere underneath.

what should i do? can i still install the catch can?
help please

you must have a 2006 or newer rx8 or the newest TSB for that hose routing..mine was the exact same way...plug the 2 maint ports also on the back of the upper intake manifold remove and plug the larger hose in this picture..
Attachment 262155

once that is done you can route a catch can directly to the oil filler neck

Erm Greg, I'm confused (I'm also looking how to route my '06). You're essentially saying to plug/cap off all 3 nozzles and just add one from the oil filler neck? Hrm..

yes, on newer rx8's and previous owners that had complaints of the milky oil on the dipstick that was the fix reroute the the passage..hope that makes sense..the TSB # 01-050/06

Okay, I'm stepping a bit out of my realm here having never installed a catch can on '06 or newer. . .

I read that the filler neck has two hose leading to the lower intake manifold maintenance ports.

To add a catch can to those.

Remove both hoses from the oil filler neck to the maintenance ports.
Cap both maintenance ports with vacuum caps.
Cap ONE of the filler neck ports with vacuum cap.
Add the hose to the catch can to the other filler neck port.
Connect to catch can.
Then you can add your breather, or if you'd like, run it back to the maintenance ports (you'll need to remove the vacuum cap you put on there to do so.

Hope that helps...

This is the way i have my 2007 routed (I set mine up the same way Kane has his 2007 listed as well)

1) Remove the "T" vaccum line at the lower intake manifold maint. ports and plug them shut
2) Remove and Plug the larger hose on the back of the plastic upper intake manifold.
3) Route Hose from oil filler neck to Catch Can (from here you can decide wheter you would like to run a breather on the open end of the catch can or route directly to your intake pipe) I have a breather on my catch can

Coo, thanks for the update fellas. Once I took the old intake off for the AEM, I noticed the excessive oil like last time I cleaned it all over the bottom of the accordion. Thank god I bought this with low mileage to not be much of an issue before installing the can.

thanks for all the info. vlaze i got the same intake as you. if you have any pics or take some of how you routed everything. please post them

Just wanted to add some more info and questions. For the '06+ models, question is why do other catch can threads state the fix from the oil filler neck to the catch can and to do so for all years '04-'08 (for '06+ it means capping Mazda's solution at the vac port on the lower intake and routing from the oil filler neck to the catch can) because this for '06+ does not solve the problem.

The schematic works like this:

Mazda's fix for the '06+ was to route from the oil filler neck down to the lower intake manifold, thus bypassing the valves above to not get crap on them. If this is so, why do I still have oil in my accordion which means this solution did not fix the issue because I have a hard time believing oil mist way down there works its way back up to my accordion when under load air is blowing down there. This means from 1 of the 3 hoses if not all of them they used for the '06+, oil is still getting in there.

I'm contemplating rerouting ALL hoses off the intake and tapping into my own oil catch can having all lines out of the intake running to it. If all they provide essentially is air for them to breathe then this shouldn't create an issue and will eliminate in theory ALL possible sources of oil from getting back into the intake. That is unless there is some vacuum pressure needed in that specific area of the intake for some of those lines which I doubt.

I'll also plug the vac. ports on the lower manifold since I don't want oil from the filler neck going back down into the intake even if it bypasses the valves; it ruins the idea of not putting crank oil into the engine when I'm using the SOHN.

Anyone have any opinions or facts as to not doing what I just described and think I should leave 2/3 of those lines in the intake?

vlaze your idea should work but i would recommend not removing the jet air fuel mix hose (usually has a yellow stripe) and keep that plugged directly to the intake air pipe..on my 2007 turbo 8 i just checked mine and my Intercooler pipes and charge pipes are very clean..my greddy catch can does have light condensation (so far the way i have mine routed is working just fine, but ill continue to keep a eye on it)

Thanks greg, that's exactly the info I need to know in regards to which hose(s) to keep on.

okay this seems a little confusing, with my 06 shinka 8. do i even need a catch can? i just got it to keep shit outta my cold air intake and for some engine dress up, but i dont want it to be a hassel.

suggestions?

man im kinda lost, do yall have any pics how to do it?

i hv a 06 gt and i just got a oil catch can so i dont know how do you install it ?

I'll chime back in here even though my 8 is long gone.

The purpose of the catch can is the keep any oil, or oil fumes, from going into your intake and gumming up the valves in your lower intake manifold.

Mazda re-routed the oil overflow hoses in the 06+ models so that this problem was much less common.

However, to install a catch can, take the hoses from the oil filler neck and run them to the catch can. Cap off the hoses that were connected to the intake. Failure to do so will cause a vac leak.

Simply capping the LIM nipples and running a vented catch can off the oil filler neck in an 06+ will cause intermittent glitches in the A/F ratio. Been there, done that.

gregs is right. The Jet Air lines need metered (by the MAF, air). The oil filler and OMP vent lines need to go to the catch can. They can then either be vented or fed back to the intake. I included the Jet Air line in the Catch Can connections. That burns the fumes from the crankcase.

Probably the best way would be to feed the OMP and filler lines into the catch can, along with the line off the air intake, and feed the Jet Air line out of the catch can. I am not sure what I did, and am not close to the car, but I do know I emptied about a cup of oil out of the can a few months ago.

Can we revive this thread? I just bought an 06 MT with the re route, and I believe the amount of blowback I'm getting is caused by a plugged cat (hopefully, as if not my next guess is a stuck or shot side seal) but that's beside the point.

The point is I took the hose off the top of the accordion (I pulled the hoses off with the engine running and the other two had vacuum whereas this one had no flow until high rpms when it became pressurized) so I ran that hose into my catch can and back to the port since the oil in the intake couldn't have been coming out of the first hose on the filler neck as it does in everyone else's pics (mine runs to a T into the LIM)

I mentioned earlier that I have some other issues causing severe blow back/by, I took it about 1.5 miles with 3 hard pulls (8k in first and second gear on an incline) and the third time I lost power and blew smoke like a diesel. I checked the can and it was 3/4 full. It's a cheapo can and has no baffles or anything at all inside so it really can't get more than 3/4 full before the cyclone effect pulls the oil out.

Either way, I'm confident that hose is the one that needs the catch for for an 06 after the tsb.
I'm not saying it's the only one but the other 2 on the accordion are pulling vacuum thus can't be blowing oil and the top one in my case is definitely blowing oil, over half a quart in one short run. For now it's back to driving under 6k rpms to conserve my oil until I figure out why it's blowing so much by -.-

If it's not pouring the rain again tomorrow I'll probably pull the cat and check it, I'm getting the code for cat efficiency below threshold bank 1 blah blah, so there's definitely something wrong with it, will find out soon if it's plugged or burned out (or the third option of previous owner having gutted it already)

I also have two other codes if anyone can shed some light on where to start trying to kill those, they are as follows: P0113 intake air temperature sensor 1 circuit high input
And: P0335 crankshaft position sensor A circuit Malfunction (cleaning the esps is on my list of to dos, cleaned the MAF but couldn't find the esps for an 06 and had limited time, the pics I saw of the esps apparently differ from an 06 or I'm just blind)

I meant to start a thread for these but every time I try to post or start a thread it says it will post after a moderator approves it and never does, why do you hate me mods? Why???