oil in the air box?
 

Well, I had some time in the garage so I wanted change the oil and check out the RX8 air box and see how they used the Helmholtz tuning compared to other intakes I've seen. What I found was some oil in the intake track and just a little on the air filter too.

Is this normal for a rotary? It has about 1,400 miles on it, and the oil level was about 1/16" over full when I got the car home from the dealer. Since it was new and I knew the thing would consume some oil I left the level where it was and broke it in gently. By about 1,200 miles I was driving it fairly hard with trips to red line most trips. The oil level was on the full mark by the second fuel fill up and about 1/2 way between full and add when I changed it at 1,400 miles. Should I be worried about the oil in the air box or not?

Well, I know it was common for there to be a thin FILM of oil in the intake on the 3rd gen RX7, but that had a lot to do with the turbochargers. To see oil pooled in the hose like that makes me think there may be a bit of a problem somewhere. I'd take it in to the dealer just to be sure.

There was another post/picture of this problem with oil all over the filter on the rx8 general discussion forum.

Nope, this is definitely NOT normal. You likely have a leak in one of your oil cooler hoses, just like I did. In fact, oil in my air filter element (I have the Rotary Extreme intake) is how I noticed it.

Check this thread for more info. Get your car into a dealership, and keep an eye on your oil. The car will remain driveable if you don't run it hard, as the leak only occurs when you rev it hard. The reason it winds up in the air filter is that the oil sprays out under high pressure right into the cooling fan, which blows it everywhere... like into the intake.

Hope this helps.

Thanks for the responces.

I don't think it's the oil cooler hose for two reasons. It's not droping any oil on the ground, the underside of the car is still clean and dry. The oil on the filter element is in line with the tube leading to the throttle body (close to bottom), not near the top inlet opening. I think the oil came from one of the crankcase vent hoses that lead into the accordian tube.

I'll drive the car for a few more miles and take another look (if the garage ever warms up). So far no massive oil consumption and no drivability issues. I still hope it is just the slight over-fill that the car came with. I was very careful not to over fill on the oil change.

Have you been to the dealer yet I'm curious to hear what they have to say?

We saw the same thing on my10ae's car and it had a leaky oil cooler hose just like Omnicron's car.

Thats what I said :D

Not good....
 

Oh, this is very not good....

Checked the air filter today, oil everywhere.

Bottom is soaked, maf is dripping, big puddle under the airbox....

Oil....
 

Picture of pool under box....

How to....
 

And for all the people who have trouble getting tyhe box open, this is how it's done....

Photo shows how the front/bottom of the case plugs into four grommets on the front wall, and the connection to the front piece of the inlet tract.

Push the whole deal back and up, until the inlet oval clears the little clip in the middle, then lift and open. Easy, and doesn't involve messing with any wires/connectors.
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doc

I've had the car for two months now and it still smells like burining old inside the car when I drive. I haven't seen any oil on the ground but I have added about 1/2qt since I purchased it. I haven't looked at the air filter yet. Have any of you with this oil leak problem had the problem of it constantly smelling like burning oil inside the car?

Doctorr:

The picture you posted is exactly what my air filter looked like. I did not have a pool of oil in the bottom of my air box though. Bring your 8 in to the dealer and have them check for a leaky oil cooler fittings/hoses. I had this problem and it is now fixed, but the remnants remain on my air filter. I did change to the K&N Typhoon. Have it looked at...

DrComputer,
This is normal - many of us experienced it. Factory protective coating burning off. If you do a search on oil, burning,smell you'll find more on this. If I remember correctly, the smell stopped around the 3rd month - probably at 3k miles for me.

You said you added 1/2qt, but did not say after how many miles. I think I had to do the same after around 600 miles. Oil consumption varies by how hard you drive your car too.

rx8cited

if you have oil in the intake and filter get your car to the dealer. it will cause problems associated with the MAF.

Who else?
 

I have to wonder how many other owners have soaked filters.....

(There is no way the oil was 'sucked in' thru the intake, from a leak somewhere. The intake half of the box is dry & dusty. It definitely came up those hoses on the intake tract.)

I only looked as part of my monthly check, had no symptoms.

With the filter being kind of awkward to check, I bet there are a lot more that just haven't been checked yet......
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doc

I was also skeptical that the oil was coming from a cooler hose.

The pics show frank oil on the clean side of the assembly. This is not a good sign, coming from the PCV system.

Doctorr, I assume the oil that was on the exterior of the airbox(dirty side) was oil originating from the clean side.

It's definitely crankcase vent related or filler neckdesign related Check your oil levels and insure that it's not overfilled. Hopefully this is not a new problem surfacing. It has nothing to do with oil cooler hoses: no connection whatsoever.

So I just checked mine (2000 miles on the clock), and I've got the same issue... with a slightly different twist. From the pics I've seen of this, folks have had brownish black oil, making it look like it's from the motor. I on the other hand have red-dyed oil, and a very light weight at that. It reminds me very much of the K&N spray-on filter oil I used to use on my Miata's aftermarket intake... but the RX8's OEM filter is nothing like the K&N material- why would there be this kind of oil on it from the factory?

Has anyone else see this red oil??

Thanks...

The issue is a bad check/PCV valve in the hose highlighted in the photo below.
This is a "known" issue and has been addressed elsewhere on this board recently.

Pull the indicated hose off of the fitting at the rubber inlet bellows and apply vacuum/suction.
If you can draw air, the valve has failed. It should only allow air to pass in the other direction.

Makes sense, but why is my oil red? are we not talking about engine oil being sucked from the motor? In an OHC piston engine, a failed PCV would be pulling from the valve cover... where does this pull from on a rotary?


allyourbasearebelongtous... good stuff : )

I think they do spray the air filter with a lightweight oil. I'll check later.

The PCV system actually "pulls" from the top of the filler neck.
The hose that is leaking is supposed to be an inlet with a checkvalve, but if the valve fails, oil shoots out of it under heavy throttle.

Youhavenochancemakeyourtime.:p

Cool- would be interested in knowing about any filter pre-treatment. I'll go check the PCV check valve now and see if it's failed. I have enjoyed some high-rpm pulls this week since I've been turning the DSC off.

Thanks...

someonesetusupthebomb!

I guess its time to head down to the dealer and have this fix this issue... :(

A few more data points...

- I took out the airbox again, this time disconnecting from the according tube so I could see what was going on further down the intake pipeline. There is a moderate amount of this red oil in the 'valleys' accordian tube.

- However, there isn't any oil beyond the tube- the butterfly throttle valve area is perfectly clean- not even a film of oil on it or around it.

- I also checked the PCV check valve, and it wouldn't let me suck (thankfully- I was afraid I would end up with a mouth full of oil :)

- I rechecked the front of the airbox, i.e. where it connects to the front of the car... not a hint of oil anywhere near the front of the box or the filter.

This tells me that oil isn't sneaking in from the motor, since it's red, and there's no sign of it around the vent tubes or throttle valve or intake manifold- it's just in the accordian tube and the airbox. I also don't think it's coming in from the outside (i.e. leaky oil cooler hoses), since there's no sign of oil at the front of the filter or airbox, or any oil in the engine bay at all, or dripping.

So that leaves the oil origin as the filter/airbox itself. Now I'm left thinking that Mazda is using a pre-oiled air filter for whatever reason, and now they're dying it red as not to confuse the techs, but in the earlier models they didn't and dirt darkened it making it look like motor oil? It seems much lighter in viscosity than motor oil, but 5W20 is a pretty light oil too... but it certainly isn't bright red.

Thoughts? I took a few pics if anybody wants to see the color of this stuff...

Thanks

-Sean