Should nipples on Oil Filler neck be plugged?
 

On the Oil filler neck, there are two nipples that I have plugged up by vacume caps. Is this correct? I was told at least one of them was supposed to go to the upper intake manifold. Can someone let me know what would happen with the car running it the way it is?


Sorry for the poor picture quality.....one nipple goes straight down and one faces towards the passanger side of car.



http://s2.photobucket.com/albums/y34...vacumecaps.jpg

im running with the one to my catch can and the other capped & have had no problems. but I have been told the same.I have only been told I should and no reason. can anyone give a reason why I should.

I know the top one goes to the UIM, its the PCV or something like that. I have that capped off on my car, but the lower one is not capped off on my car and I have no idea where it goes.

IIRC 95 and up came with that nipple capped.

The whole reason I started looking at this was the car smokes like crazy on decel. It's definately burning oil. Someone told me they thought my PCV valve was backwards causing too much pressure in the "Crankcase" (even though it's not really a crankcase).

Can anybody else shed some light on this?

You need to depressurize your crankcase----capping that nipple would be the worst thing you can do.

I recommend drilling into your compressor inlet, tapping it, and threading in a 1/8th NPT nipple. Run a vacuum hose from your oil filler neck nipple to that nipple, and while you're at it I recommend T-ing your oil metering injectors and running a line to that same nipple on the compressor inlet. You can see how I did it in this picture:

https://www.rx7club.com/attachment.p...hmentid=214267

By doing this, as throttle increases, the turbo draws more air through the vacuum hose, and your injectors meter more oil onto the apex seals, and your crankcase becomes (more) depressurized :)

You need to get your positive crankcase ventilation system hooked up and working. This diagram will help a bit.


http://www.autosportracetech.com/RX-....htm#IntakeOil



Consulting the service manual wouldn't be a bad idea either.

I hope this fixes the problem....I am hoping I don't have a problem with a bad turbo or motor! I just don't understand how my last motor didn't smoke on decel with both nipples plugged up.


Maybe it has something to do with this motor used to be a premix motor.

Just run them both to a catch can... Make sure you buy a can that has a vent on the top.

I have deleted my emissions on my 1991 JDM savanna GTX. I have a vac cap on the top oil filler neck nipple, then i ran the bottom nipple to the charcoal canister... is this correct???


-Ben

I have deleted my emissions on my 1991 JDM savanna GTX. I have a vac cap on the top oil filler neck nipple, then i ran the bottom nipple to the charcoal canister... is this correct???


Edit* Sorry for the double post. Internet explorer error.

-Ben

This works for some, but for those having bad smoking problems, introducing the 'sunction' action of the compressor wheel into the equation really helps depressurize the crankcase.

Thanks for the help guys! We will see if it works.

I dont see how the car would still smoke if both lines are venting to the atmosphere. Also some oil can go into the turbo if tapping the inlet of the compressor. This is why I just decided to send them both to the can. Who knows whats right, I guess whatever works for each person... :bigthumb:

Rich you done with A-rods car yet?

Are you sure the smoke isn't from the 100ft burn out you did? Saw your video on Youtube...

LOL...I didn't know there was one on Youtube? Do you have a link?


The only ones I know about are the 2 on Streetfire.net if you search under
burnout RX-7

I ended up running the top nipple to a PCV valve and into UIM. The bottom nipple I kept plugged up. I wanted to try this first as drilling into the compressor inlet kinda scares me! It seems like it would suck oil into the turbo.


Anyways....It seems like it has helped a little. It didn't start smoking right after I let off the gas like it would before. It took a few seconds and then started smoking but not for very long.


Any other ideas besides drilling into the compressor inlet? I will if I have too, but would rather see if theres another way to get rid of it.

Someone correct me if I'm wrong, but the way I read this from the PCV schematic you've only done half the job.



"When intake manifold pressure below atmosphere pressure, the blow-by gas flows through passage 1 and is pulled into the intake manifold.

When manifold pressure at or above atmosphere pressure, the PCV valve closes and blow-by gas flows through passage 2 and is pulled into the intake portion of the Primary Turbocharger."

Michael, there's nothing wrong with sucking a bit of oil into the turbo......my FD doesn't smoke a bit with my current setup.