I picked up a 2004 which already had a 3" hi-flo oil soaked air filter on it. Its been super windy and dusty recently and last week when I started the car up the rpms were bouncing around like crazy - from 3000 to 0. I had it towed to a dealer and they say the oil-soaked filters screw up the air flow sensor. They cleaned it out, charged me $120 since it was an aftermarket item, and sent me home. At 75 mph or greater it still chokes and falters. The cost to put the stock filter and cover back on, in dealer prices, comes to $510. Anyone have thoughts on reliable alternatives or where I can get used stock parts. For that kind of hassle and money I can live without the extra few hp the hi-flo filter may provide.
Delmer

 

What a rip off! Sounds like they didnt clean the maf? This problem could be many things my friend--from plugs, coils, airway issues, cat etc---got to find a good dealership or start a diy study
olddragger

 

Reading other posts here got me wondering and I took the filter off again myself. There's not much there right now to go by, but I am fairly sure the oil 5w30, not the stuff from the filter. Trouble for me is that the closest dealer. the one mentioned above, is 120 miles away; the next closest is over 200.

 

Doing more searches on this site have turned up some lengthy threads where others have had oil in their intakes, from as early as 2004, but I never did find any clear solutions. The main theory seems to be a bad check valve which allows crank oil to vent into the air intake -particularly after a high-rpm run. In my case it happenned at around 22000 miles, about 1500 miles after an oil change. In the previous 3000 miles between changes I had not had to add any oil at all, though it was getting low by change time. Now it has gone through it's safe range on the dipstick in 1500 miles. With the amount collected in the baffles of the intake hose its obvious where it went. There is also condensation on the dipstick.

For added pleasure, the dealer says its related to the aftermarket air filter so thay can't do anything further (which from posts on this site has no relevance), and Mazda 'Assistance' says they rely on the dealer. Apparently I'm supposed to take a week or more off work to travel the country till I find a dealer who knows something about these cars.

 

I have run a K&N in my car almost since new and I have not had any problems, granted, I do not have the mileage that you have, but the amount of oil in the K&N is very small and the oil is very thin, doubt it would clog the MAF by itself. Chances are the one you had might need to have been cleaned, typically I clean the K&N's every 10k, at most 12k which reminds me, I need to do the one in my Tribute... Anyway they pick up dirt and maybe it picked up enough that some blew through and choked the MAF, which needed to be cleaned and since the dealer charged you, they should have a) changed the filter and put a new OEM paper/cotton one in there and cleaned the MAF. If they did not do that, then they are negligent.

As far as oil entering the intakes, there is a return or blow by from the engine on Piston engines, that vents to the intake tube and you will get some oil in that that will get on the filter. I have not looked to see if they same scenario exists on the Renesis. That being said, it sounds like the MAF should be removed and cleaned CAREFULLY. Not sure the best solution to use, and the air box should be opened up and cleaned out good too, just to be sure. This should fix any issues related to the idling. I would also recommend that you take it to a dealer and have the latest flashes and cold start TSB done, since it is due for plugs in 8k. This would be worth the trip, as the plugs alone cost $125 for the set.

 

Same thing happened to our Porsche. Tried every option, only one that worked was replacement with a stock filter and a new MAF sensor. And you'll pay out your **** for a new MAF sensor.

 

Something else that might cause this is a leak leak in one of the oil cooler lines. At least in my case.

https://www.rx8club.com/series-i-trouble-shooting-95/leak-oil-cooler-line-58015/

 

Nope, no exterior oil leaks, its pretty definite now that it is blow from the crank. Got off the phone with the tech again this morning. He says when he goes to his Mazda repair website and plugs in "oil in intake" the first thing that comes up is after market air filter. I pulled the hose that runs from just below the oil cap down to the air intake and there are no valves on either end. As Michael says with his Porche, it appears a return to stock is the only way. Then at least if it still happens the dealer has to deal.

I don't see a buy/sell section on this site (have I missed it?). If anyone has a modified filter they are happy with and wants to sell their old cover (N3H1-13-Z01G) I'd be happy to take it off their hands.

 

I added an oil catch can (as used on turbo RX-7s)on the rear of the airbox. Put the lines into it, then on to the intake tube.

Right now, there is about an inch of oil in the bottom

S

 

Stealth
You have a NA car --right? Blowing that much oil? ??????????????
Olddragger

 

I didn't expect to see any oil in there, but noticed a drip because the bottom gasket was loose. Took it off to coat the gasket and tighten it up, the level was just below the sight tube on the side, so maybe 20mm from the bottom, not yet showing in the tube.

Had it on for maybe 8k miles.

S

 

The catch reservoir is one way around it, easier than fighting Mazda, and allows me to more closely monitor how much is forced out, thanks for the suggestion. For those who may come across this, the breather hose allows vapors from the crankcase to vent and burn as opposed to building pressure and blowing seals.

Did/do you own a Dodge Stealth? I traded in my VR4 last summer for this guy. I'm ok with the RX8 but do miss the GT.

Here are a couple related links from this site (from 03, 04). Curious that no one reported back with dealer responses:
https://www.rx8club.com/series-i-tech-garage-22/oil-air-box-19733/
https://www.rx8club.com/rx-8-discussion-3/oil-intake-system-19724-printthread/?pp=40

 

there is no PCV to stop the oil from going back into the intake. there are 3 reasons they will say for oil in the intake when there isnt an outside oil leak source

1. over filled oil
2. spilled oil when filling
3. Blow buy


https://www.rx8club.com/showthread.p...highlight=blow

 

I guess my only comment on this is......

if it's blowby...and it only happens say on 1/10 of the cars...doesn't that mean that there is a problem with said cars....ie the blowby is excessive. Probably meaning side seals/oil control seals are poor.

If so doesn't this mean that there should be something done abbout it??

I have been told that the side seals can be quite poor before you see a really big drop in compression.....that the bulk of the compression pressure is from the apex seals...and that side seal problems might show up as subtle drop in compression.

Comments

 

all I know is never shut your engine off at 8k! It will blow one hell of a lot of oil into the intake. I have seen a car on the dyno go into a fail safe mode or something(we still dont know what happened) and the engine just shut off-- I mean like turning the ignition switch off. At 8k in 5th gear. Scared the ehll out of the owner. The car cranked and ran ok afterward but there was one hell of a lot of blow back oil in the intake. Also no more blow back oil into the intake with normal or spirited driving. What is excessive blow back for this car?
olddragger

 

Guys,

I am trying to picture how oil is getting into the intakes from the various issues. I ask because my dealer did in fact overfill my oil at last change - last week. (yes, I know do it myself...) I have the REVI with Ram Air. I will pull the filter out tonight to check but am just trying to picture the mechanisms for oil to get into the CAI.

I can understand the oil cooler leak and it getting sucked into the CAI - that is straight forward.

How does it get into if the oil is overfilled?

Where is it "blowing by" and in which direction does it come in the CAI? e.g in the direction of air flow into the engine or the other direction (which would seem to be blow back... )

Thanks

 

Blow back into the intake comes from the little vent tube by the oil filler hose....

if the engine "blows by" combustion gasses .....it will pressurise the "rotor housings and that pressure will push out the vent into the intake.......taking with it oil dropplets...or worse.

If this is "normal" them they need to install a catch can type of arrangement...I'm kinda tired of replacing my oil filter

 

Thanks that helps.

Which side of the filter will it be seen - the air "in" side or the air "out" side of the filter? I guess I am asking where the vent enters the CAI...

 

Vent is in the accordian tube between the MAF and the throttle body. Oil from this will be on the TB side of the filter (inside)...and will predominately be on the center lower half of the filter where it drips down from the tube the MAF is in.....

 

Deja Vu

 

"out" side as dan described above

 

Or dripping down the crack between the filter housing into the tray beneath...very deja vu.

Not very funny though...and I don't think I should have to put up with it being "normal"

 

I can't see how the dealer is blaming this on your aftermarket filter. Isn't Mazda itself coming out with a CAI that uses a similar if not a K&N filter? I think the answer is the catch can and maybe a side and/or oil seal review.

 

Here are some pics of my recent discovering of "Excessive blow by" to my 2005 Mazda RX8... Fun times...Glad I went to change the air filter myself. I loved finding oil in the tray under the "airbox" and then oil dripping out of the "Duct" in the last pic I posted. So I dried it all out today...changed the air filter...Just going to monitor exactly how much "Blow By" I am having...Did add "Lucas" additive to the oil. I love my RX8 so I will continue to take care of it! Love Love Passion! Fun times!