Ole Spiff

Has anyone heard of an issue with the RB Rev8 intake causing oil to be pulled from the engine into the intake system? I had a Mazda dealer mechanic tell me that the RB intake creates enough vacuum to cause oil to be pulled up through some kind of a bypass tube? And that caused motor oil to be in the bottom of the intake hose and was on the MAF?

Anybody heard of anything like this?

marshall

I've never heard of this happening, technically it's possible for the oil to get up into there because there is an overflow tube, but I would personally be more worried that it was for some other reason (hot oil + overfilled oil maybe) than the intake is creating "too much" vacuum.


I suppose it is possible that it could be because of the intake if there is a lot of oil in the engine, but I doubt they generate enough vacuum to do it. Of course what do I know.


Maybe it's the intake, although most people here will tell you you're crazy for blaming anything on a RB product, especially their most popular one.

mysql101

My RB intake never had this issue. But my stock intake never had oil in it either.

My guess is that if your car gets oil in the intake filter, it will do so with aftermarket intakes too.

Tamas

iTrader: (1)

It's always the easiest thing for the dealer to blame an aftermarket product for any issue.

Nopstnz

^^ Agreed.

PerformRX-8

Actually this can happen to any intake that you have RB,AEM, HKS etc... even the stock. Most of the time its caused by overfilling the engine with oil during an oil change.... You don't really have to check if there is oil in the intake tract becuase if there is oil there you'll get a CEL..... so if you don't have anythign weird happening or CEL you're fine!

Ole Spiff

I just had the oil changed a couple of weeks ago. Weird DID happen; the engine suddenly lost half it's power and was smoking. When I took it in they gave me the "it's your RB intake" thing. Said the increased vacuum of the intake pulled oil up through the overflow tube. Yes there was motor oil in the bottom of the intake tubing.

Ole Spiff

Latest update: After putting the factory intake system back in place and running a computer check, it turns out the catalytic convertor had melted the oxygen sensor. Don't know why they didn't see that before pulling out my RB intake and putting the factory intake back in but that's where it's at right now. They've ordered a new sensor and cat. After they install those they'll check to see if anything else needs attention.

I'll update everyone with whatever I find out. So far it certainly doesn't appear the RB intake had anything to do with the situation.

swoope

iTrader: (5)

note,
make sure the funnel that you use to get the oil in extends past the tube that runs to the intake....

food for thought.

beers

olddragger

iTrader: (3)

Yep that is a good idea and one I have passed on to the mazda service dept here in my town(good guys--one ran a 13 b for awhile). When checking the intake for oil ,try to notice if the oil is dirty or not. That can be of help in diag the problem. If it is clean oil then you know what happened. if it is dirty oil then it is obviously another problem. Some of our cars do have some blow back issues. I have just ran a downdraft tube instead of hooking it up to the intake.
Olddragger

Razz1

How does a melted O2 sensor affect oil in the intake?

I think you barking up the wrong tree.

Tamas

iTrader: (1)

Of course it had. Next thing you'll hear from the dealer will be that since the RB intake supplies too much air to the engine, it caused the oxygen sensor to melt.

Ole Spiff

Got my car back and here's the final result:

They replaced the catalytic converter, the O2 sensor which had melted from excessive heat by the cat, both ignition coils on the front rotor, full set of plugs.

They didn't say the RB intake was the cause but did recommend I not reinstall it. They replaced the plugs and the battery a few months ago so I found it odd that all these electrical problems were suddenly in need of attention. There's no question the cat had to have malfunctioned which would cause the O2 sensor to melt...but the other problems? Could a melting O2 sensor cause all that??

flyboi1121

Got my car back and here's the final result:

They replaced the catalytic converter, the O2 sensor which had melted from excessive heat by the cat, both ignition coils on the front rotor, full set of plugs.
----------------------------------------------------------------------------------------------------
so do what i did... get rid of the cat

rotarygod

The RB intake didn't cause this issue. It is something that people have reported in stock intakes as well. It is a result of the rotary equivalent of the crankcase ventilation having it's tube run back into the manifold. Some will say that you can't get any oil up there unless you are under boost where pressure can bleed off behind the seals and pressurize the oil pan area to a point. This is false. It can happen but it doesn't do it because of the reason people think it does.

All of the oil to the rotors comes into them from the eccentric shaft. The oil drains out the sides into the end housings. The center housing has it's ventilation tube above where oil from 2 rotors drains back into the pan. When the engine is spinning fast, this oil doesn't just fall down. It can splash a little bit and mist up in the system. This mist can travel up and out the ventilation tube and into your intake. It's like condensation. A little bit doesn't do much but it can accumulate into a larger amount.

What the tech told you about higher vacuum from the RB intake is wrong and shows his ignorance for how things work. If the RB intake does flow better there will definitely be a pressure change but it won't go down. Press would go up. Remember the higher the load you are under, the less the pressure in the system. The more air you send into the system, the higher the pressure you are at. It would be lower intake pressures that are farther into vacuum that would theoretically make your problem worse. The opposite of what the tech told you is true. Remember that the vent is after the throttlebody though which means that realistically speaking, the pressure in that tube should be about the same as it was stock. Maybe slightly different but it definitely won't make your problem worse. The tech is an idiot.

BoosTED

iTrader: (2)

My stock intake had standing oil in the flexible intake hose. That is why I installed the Greddy catch can that I had gotten knowing I would use it with forced induction.