Oil in Air Intake
 

I have a stock 2004 RX8 Auto. 155,500 KM's at the moment. Engine was replaced under warranty at 153,000 KM.

Early last week, I lost power steering. Opened the hood to check out the power steering harness connectors, and I noticed oil dripping out of the air intake filter box on to the tray. I ended up cleaning the intake filter box up to the accordion tube. Bought a new paper filter, and cleaned the MAF sensor. Read up about this problem, and decided to ordered an oil catch can online. I also seemed to of fixed the power steering issue by spraying PJ1 contact cleaner on the top two connectors on the PS harness.

Just a week later (this past Friday), after accelerating hard I noticed a ton of bluish type smoke coming out of my exhaust. Checked the engine bay, and there was oil dripping from the air intake box again! Cleaned out everything as last time, but put in a new K&N filter. I also disconnected the throttle body cleaning both sides of it. There was a bit of oil residue on the inside of the upper intake manifold, but I was only able to clean the first part of it, up until the bend. Didn't want to take the whole upper intake apart in order to clean it out completely (read the DIY, looks complex), so I just put everything back together. This time I re-directed the oil filler tube into a temporary make-shift catch can (still waiting for the real one to arrive), and placed a plug on the intake. Started it up, and again bluish smoke started blowing out of the exhaust for a bit, and then it cleared. I assume it must be the residual oil being burned out through the exhaust. By the way, I never over-filled the oil. I always made sure it was below the full mark. Also before putting everything back, I extended the coolant drain hose so it doesn't drain on the power steering connectors.

Is there a way to clean out the rest of the oil residue in the upper intake without taking the whole thing apart?
Also, other than the oil-filler tube, what are the chances of the oil coming from the other two tubes on the intake?

I just noticed exactly the same problem today in my airbox. I'm also driving a 2004 AT. However, I only had the airbox out as I was replacing the ignition coils.

Take apart and clean.

Then two week later, re-clean the MAF again.

Anyone have any other suggestions? Like I said, I don't want to take the whole upper intake apart.

Will zoom-zoom or seafoam remove that left over oil residue?

Would it also be possible to run a flexible wire brush through it without damaging anything? It looks like the upper intake splits into two chambers.

My MAF definitely was coated with oil.... as was my K&N filter. I never overfill on oil changes. Isn't that the reason for the oil filler tube? To route extra into the airbox so it has some place to go.

Anyway, excuse my ignorance, but why would recleaning the MAF a few weeks down the road eliminate oil in the airbox?

You need to install an oil catch can as I did, to prevent this from happening again. Get one off of eBay cheap. See HERE for DIY. After having oil dumped into my intake twice, got fed up and ended up rigging up a temporary catch can last week as shown HERE by just using a plastic bottle, re-routing the oil filler hose into it, and putting a plug on the intake (I recommend doing this immediately). My real catch can just arrived a couple of days ago, and I just installed it.

From what I have read, the oil filler tube is to exhaust oil vapor (not oil) and relieve pressure. Because of emission laws, it can't be exhausted into atmosphere, so Mazda decided to vent it back into the air intake so that it can be re-used. Problem is that oil can get blown back into that tube, making a mess of the air intake and gumming up your SSV valve causing it to be stuck and possibly other major problems.

What I need to know is how to clean the upper intake without taking it apart. It's a PITA to take apart, and don't feel comfortable doing it.

Which catch can did you end up with? I looked at a few Greddy models today but they're expensive for what is essentially a trash can, lol.

Carbon fiber raceroots, which is also expensive but comes with all the hook ups and I like the look.

But any of the $19 eBay catch cans will do.

I had oil-in-the-intake in the winter of 2003, and described the problem with oil blowby.

I got a cheapo can off Ebay, that even said 'MazdaSpeed' on the top. The mechanic started to give me shit for putting aftermarket bits on my car at the service check, then came back half-an-hour later and apologised - "Sorry Man, I didn't see it was an official Mazda part till just now..."

There is much wisdom/experience here......

Don't need catch can, just a filter at the oil filler cap.

How is taking the UIM apart complicated or hard? You just need to keep track of where each of the stupid hoses go. To do that I would just do one section at a time. The hard part comes along when you need to seperate the UIM from the LIM...which you don't have to do to clean the UIM.

I removed my Upper Intake to clean it. No need for new gaskets, it has orange rubber ones. instead of paper lol

anyways theres 2 bolts that are extremely difficult to get to next to the firewall, otherwise its cake.

Same problem
 

2004 6 speed Grand Touring.
the car would not start. Checked and cleaned plugs. Still only cranks no fire. Checked for spark same thing. So I went out school thinking it was flooded. I grabbed a can of starter fluid looked for a place to spray it in, in front of air intake valve. The only place available was the vacuum line to the break booster. As soon as I pulled it off the car coughed and tried to start. I then realized the engine was not getting any air.. So I pulled off the air intake found a ton of oil inside the corrugated hose oil all over the mass air sensor and pubbel of oil in my air filter box. The filter of course plugged with oil choking the air completely even though the rest of the filter was clean. I cleaned the whole air intake. Cleaned the Mass air sensor. With the plugged filter removed the car started rite up. I park my car facing down hill. The oil from the vent was Collecting in the intake running down into the air filter box. That is pitched the other way making a puddle of oil rite in front of the intake only to be sucked back up on the filter.
If you look the oil fill cap is also the vent. It is easy to poor oil into your air intake.
I an going to put a oil catch can on the vent and plug the vacuum line to the intake.

Usually oil is barfed through that line by blowby pressure, rather than poured in (which of course can also happen, just not as often). A catch can will help, but keep an eye on it. Excessive blowby is not great.