There have been some renewed concerns about oil found in the intercooler, intake elbow, throttle body & UIM.

Over the years many who track their cars (road course, not drag) have noticed both, high oil consumption & oil contamation in the intake track. I was one of them.

It's suspected that oil travels up the filler neck during hard cornering & braking. Plus the hose connected to a hard line that runs to the primary turbo elbow at the air box is always under a vacuum (idle or full boost).

As many have diagnosed, its source is the breather hose connected to the oil filler neck.
It's literally sucking the oil out of the engine that sloshes up the oil filler neck.

The 93 & 94 FD also have an additional hose to the PCV (deleted on the 95 models)

Numerous write ups on the subject have appeared in old threads. I just am illustrating how I corrected it in my car. Now I know there is more than one way to skin a cat. How you go about it is up to you. I'M just going to cover how I did it…………



1st I ground off the two plastic nipples on the oil filler neck. I did this so I could tap threads for another nipple that extended into the center of the oil filler tube. The idea was any oil traveling up the oil filler neck would gravitate towards the sides. Unless the entire oil filler neck was saturated with oil, the center would only vent oil mist.

2nd I got a small 16 oz oil catch can. There wasn’t much room to fit anything bigger in the location I selected. After a full day at the track I seldom get more than ¼ ways full (4-5 oz).

The catch can is not vented to the atmosphere. I routed the other hose to the original hard line under the oil filler neck to the primary turbo. The thought was if I vented it overboard & the catch can did overflow it would deposit oil onto the engine & rear tires.

Since I did 6-8 track events this year IM pretty confident I could have got away with a vented catch can & just monitored the oil level.

The only negative is during oil changes. The funnel doesn’t sit in the filler neck anymore (I have to hold it), the extended nipple blocks it.

 

Nice, I was thinking of making a restictor plate or baffle to fit between the fillerneck and housing, but that looks like a better idea. One observation in general on oil in the intake tract, one should always use a funnel when adding oil. If you are standing at the passenger fender adding oil straight from bottle, you are floodding the area where the hole is for the PVC tube. It's likely some will go down the tube.

 

Elegant. I like it.

Dave

 

Good work. I think I am going to give it a shot.

any con's in doing this yet?

thanks for the write up,
-josh

 

Great idea, I will have to give this a try!

 

what size nipple did you end up using?

 

Yeah, where'd ya get that nip?

 

this is what I used

http://store.summitracing.com/partde...5&autoview=sku

Both of these will also work

http://store.summitracing.com/partde...5&autoview=sku

http://store.summitracing.com/partde...5&autoview=sku

 

awesome thanks, im going to do this when i go home

 

That first one doesn't look like what you have in your pictures at all. what you have must have threads in the <middle>, since you have a tube projecting IN to the filler neck, and a tup projecting out for the hose....

 

It looks like he used the first nipple, ground the threads off of the threaded fitting, and cut the hose barb off of the other end.

Dale

 

Then what is holding it in place, epoxy? Why did he do this:
The description doesn't match the pictures.
It looks to me like you need to add an extension tube on to the pipe threaded end. Or bore out the original nipple and insert and epoxy a piece of thin wall tubing that extends into the center of the tube. Good idea though.

 

The pics were of the 1st one I made. Now an extra laying around in my assortment of spare parts.

The description was more relevant to the 2nd one I made.

In the 1st one I drilled an undersize hole in the filler neck after grinding off the plastic nipples.
Notice I also cut a 60' angle on the nipple? I pressed it in using my vice.

The 2nd one I used the stainless bulkhead nipple.

I selected it so I could bend the barbed end at a 90' angle.

How did I do that? I put a piece of heavy gauge house wire through the fitting. I was then able to bend it without kinking. I used my propane torch to melt the insulation off the wire so I could easily remove the rest.

The threaded end was screwed into the filler neck.

That's why I showed a couple of versions of the nipple. You can either press fit it or thread it.

The main point was to breath from the center of the oil filler neck & not the side.

What others have done it to drill through the oil filler cap & run a tube down a couple of inches. Then attach a hose from the cap to a catch can. This works great also, but I have a mega bucks aluminum MazdaSpeed oil cap. No way I'M drilling into that sucker.