Installing catch can on R3
 

Heres a chance for someone to prove their knowledge!!

So im installing a breathable catch can on my car due to a recent MAF issue I had concerning too much oil on it! ;)

Its a little bit different than installing a catch can on an 04-08 due to the vacuum lines being changed, so...

My plan is to take the line coming from the oil fill tube and running it to the catch can. After doing this, there will be two open maintenance nipples on the LIM that I will have to cap. Since Im using a breathable catch can, Im under the assumption that this is all I need to do...BUT the Series IIs have two other hoses running to the intake, Im not sure if I need to do anything concerning these hoses, like removing or capping anything else? Any help? Thanks.

I thought they changed the vacuum lines on series II's to combat this problem.

As did I, I bought a catch can when i first got the car, and realized that the car's oil filler nozzle has a vac line to the top of the motor.

Sounds like the S2 is the same as the 06 or 07+ S1. Ok 2 ways you can install a catch can.

option #1 and this is the simplest method. Put the catch can inline with the hose from the filler neck to the service nipples. Done. Just make sure the catch can is air tight, otherwise you will be creating a vacuum leak.

This method is utilizing the stock system and just improving on it by catching any oil that may go from the filler neck to the service nipples (LIM)

Option #2
Same as above but you must cap th service nipples and both end of the line that runs to the bottom of the oil filler down by the dip stick. That line runs to the intake tube post MAF. Must cap at the intake tube and at the bottom of the oil filler.

Advantage is there is no way for oil to get from the crank case to the intake tube.

Variation of Option 1 is to go an additional step and install a check valve in the line between the lower oil filler and the intake tube to insure no oil comes up and only air is being pulled through. No oil shoudl be able to get pulled up through that line, but back pressure in the crank case at high RPM could push oil up, so take the extra step.

At Idle that line has vacuum because the throttle plates are closed. However, once you open the throttle the vacuum on the lower intake is equilized with the vacuum at the intake tube making no possible oil flow in either direction.

I like option 2 with a check valve, its what I do and it works.

pictures ?

Cant, doing another motor swap.

FYI, I have an 07. But its a very simple concept. Fine the 2 breather vacuum lines, the one from the service nipples which goes to the top of the oil fill neck and the one at the bottom. Trace the bottom one to the intake tube. Disconnect it and cap the intake tube real fast and place your finger over the line to the lower oil fill tube. Notice there is vacuum. Now Disconnect to line at the upper full neck capping the line to the service lines. Notice the vacuum from the lower oil fill line has gone away. By simply placeing the catch can in line, you are catching any oil. You could also place it in line between the intake tube and the lower oil fill but I had more room on the other side of the engine bay.

You don't want to vent the oil fill to air! It will drive the a/f nuts in certain situations.

Need some clarification here:

So, can option 1 be used with a breathable catch can if the service nipples are
capped? And if so, does anything else need to be done?

And is option 2 just a "do this if you want to, but you dont have to" in addition to option 1? And if so, why is it there in the first place?

NO!!!

Option #1 must be used inline with a sealed catch can, meaning not vented or breathable.

Option #2 is for vented catch cans. Basicaly you ar ehaving to cap all the vacuum leaks you create by opening the breather system to atmosphere. That means the service nipples, the nipple at the intake tube that goes to the lower breather nipple at the bottom of the fill tube and of course the nipple at the bottom of the fill tube, otherwise any oil that might go to your catch can will now be on your engine or undertray.

Honestly, the most effective way to keep oil out of the intake tube and maf is to install a PCV valve or a check valve between the intake tube and the lower oil fill tube. That keeps oil from coming up but allows the stock breather system to do its job.

that is an interesting concept

Gotcha. So if im going to use a vented catch can, Im running a hose from the oil fill neck to the breather can, capping the service nipples, removing the bottom fill tube hose and capping both ends, and leaving the jet air fuel hose in place. Thanks.

For information purposes I am attaching the intake diagram for 2009+
Attachment 234865

if you end up doing this please do a DIY.

Just top up the right amount of oil... problem solved!

Don't get WHY you think you need a Catch Can for a Series 2...?

Mazda changed vac lines etc, so it is not needed, sorry if I am missing something here.

IF you are getting engine oil in your intake (near throttle body) then I suggest either you are putting in too much oil, or you have altered the OE vac line set up?

I dont overfill, and didnt alter anything, I am anal about filling and never fill it to the top of the dipstick. I was throwing p0171 (lean), and the cause was the MAF, there was oil buildup on it. The tech called mazda, because we were both under the assumption it shouldnt happen on an 09+. Mazda said the change will combat it, but it will not eliminate it, and that what I experienced is considered normal by them. Thats coming from mazda themselves...After hearing what Mazda said, Im gonna throw a catch can on. No reason not to if the car is not immune to this.

OK...this is the first I have heard of this for S2..

I have seen no official bulletins or tips for this..so will be interesting to see.
I know mine is as clean as a whistle?

But then again given MNAO questionable Service information I am not surprised...

I am sitting on a current Dealer M-Tip PDF newsletter put out by MNAO Service on 'engine stalls after replacement', (PO172 Fuel trim too rich)) they (MNAO) suggest checking Injector harness wire color connections and or correct Injectors and position.

For the 2009-2011 Injector colors and location they are wrong and don't seem to want to listen to Dealers who have submitted a correction...
They say Part Number of Injectors are Blue and Red, when they are Dark Green and Dark Red/brown.

Thread revival. Sorry, but for us less experienced folk would someone mind labeling the lines and tubes? Hell, even just highlighting the lines that need removed would be great. In my case, which line in that diagram is the "bottom fill tube hose"? Would that be the line next to the words "VDI Solenoid Valve"?

Thread revival part 2! Where does the second tube go on the oil fill? I know the top one is the one to the LIM, but where does the bottom one go? I can't figure it out and frankly don't feel like pulling everything apart to find out (unless I need to anyway). This is the second time I have had oil in my intake. First was due to what I thought was pepboys putting too much oil because I told them not to replace my filter. Emergency situation for the reason I went there for an oil change. Second time was when the dealership changed mine. So a catch can I do need!

IF you have a R3 or S2 catch can should not be needed in a sound engine, unless someone has been doing lots of under the engine mods.

Oil in TB is not an issue, the venting and plumbing was changed and prevents oil from forming there.

Anyway, IF you have a S2 one of the hoses comes from the two EMOP's and is the return system of OIL from EMOPS and also when their cleaning cycle occurs, the oil goes back from EMOPS through that tube and back down oil filler to oil pan.
This hose has a click on type fitting onto Oil Filler Tube nipple as it carries return oil under pressure (small)....see EPC sketches below in red.
Blue is the LIM hose connection.

EDIT: Are you filling engine oil quickly while engine is still running?, if you are adding too much oil and OR if overfilling, see the GREEN mark arrow, oil if overfilled will come up/rise from engine into vac tube (green) which goes to a straight hose joiner which then ends at 90 degree connection in the black concertina air intake hose before Throttle Body..

The other same 90 degree connection in black concertina air intake routes to the LIM and is for emissions, no oil can ever come from/to this hose...see Orange.

The rest of the smaller thin hoses are for LIM SSV Actuators via two small solenoids (18-741C) under oil filler tube box.
Plus the hose (13-990) for Air Pump via small solenoid (18-741C).

A separate small thin hose via another small solenoid for the VFAD (Fresh Air Intake Flap), which eventually goes to a small nipple under corner of the black hard square intake directly after the TB.

Are you certain you are not overfilling your 09?..
Engine performs OK?
No heavy oil exhaust fumes..
How many miles?

NOTE: The S2 already has a factory 'catch can' which is part of the large oil filler 'black box' which drains back into oil pan, installing another catch can is worthless, IF you own a S2 and are seeing engine oil inside around Throttle Body or inside black Intake Concertina Hose there are other issues with your car.
1. Too much engine oil is being topped off or being overfilled.
and or..
2. Engine has compression 'Blow Back' which usually means damaged/fractured Oil Control Rings or worn out ones, ONLY rectified by a complete engine overhaul.
and or..
3. Possible modifications from the original factory engine, or other mods performed by other owners.


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This is immensely helpful. I unfortunately have not been the one doing my oil changes. Pepboys did one and I am sure they over filled and Mazda did the other when these problems occurred. I would like to believe that Mazda didn't over fill, but well not everyone knows what they're doing when it comes to an RX8.

I was just really confused how the oil was getting there.

My engine is fine other than shaking from needing new mounts. Need to get that fixed. I would like to believe that couldn't cause this problem, but I guess I never know.

No heavy exhaust noted and I think I am at 47000. Maybe 43000.

I just woke up and can't fully brain right now.

I will still be installing a catch can on my car though. I would rather have it and not ever need it again than not have it and possibly spend hours cleaning my intake and replacing my air filter again.

I guess now the hard part is finding fittings that will work for the air intake port.

I really wasn't expecting this level of work to go into the response I got.

Thank you again, you're awesome!

Good read.
Nice work on the Diagram Ash.

Just my 2 c
But even on the S1 I'm not really in favour of a catch can... I'm boosted now and still do not really see a need for a catch can.
I've never had to empty mine ... currently I'm doing repairs but when I re-assemble (johnny 5) I'm just going to VTA.

I guess what I'm saying to help add to the topic is I'm really not sure this is a necessary modification.
Again just my 2c

I'm surprised you don't need one being turbo since crank case pressure is increased. I have -8 AN lines and fittings on mine and get a bit in mine. Before this setup I would get even more with my vented Moroso catch can.

Mine is recirculated and has a dipstick to check the level.

https://farm9.staticflickr.com/8686/...021103c9_h.jpg

You just wanted an excuse to show off your beautiful bay :)

My 2 cents to add to the discussion: I've got an '06 with the modified plumbing and I was getting more than a little oil in the intake with the turbo until I put in a can. This can is not airtight sealed tho so I left it VTA. I haven't noticed any issues with this. It collects a few ounces every month or so, depending on how much I boost.

10 years of ownership, competition, and even running an overfilled oil sump (early on I had no clue that this wasn't necessary) and I never had one drop of oil in the intake and no need of a catch can. Unless you went FI there isn't any need for one at all and even then it's questionable.

Oil in the intake on an NA engine is an indication of excessive blow-by and the fix is to overhaul the engine.



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I can say that prior to FI I never had any sign of oil in my intake. When I pulled out the stock air box to put in an MS CAI it was completely clean inside. The CAI was clean when I pulled it out for the turbo install. I only got oil in the intake after FI.