EHM to Airbox Mod

Rixram · **Posted:** Thu Oct 07, 2010 11:53 am

My EHM fix was actually very easy to accomplish.

I needed a drill, a length of hose to go from the PCV vent (Positive crankcase ventilation) to the air box, a fitting to attach to (easily bought from a boat supply store or similar). You will also need a plasticy-cork from a wine bottle (yes, really).

I'd recommend you do this yourself, but try a dry-run before-hand to familiarize yourself with parts.

How to:
-Remove engine Oil cap, then the plastic engine cover.

-Use a flat-tip screwdriver to loosen the fittings on the hose attached to the PCV assembly.

-Once hose removed from PCV, gently pull hose and "plug" from the air intake to the turbo.
--Once removed, take your cork, preferably the mostly "plasticy" kind, and squeeze it into the now empty plug by the turbo inlet.
-Undo all attachments to the larger section of the airbox.
--The lid comes off the top, and several screws hold the base to the engine compartment -Locate the backside of the airbox, and MARK ONLY the position to drill your 1" hole for your hose fitting.

-Place (not screw in, just physically place) airbox bottom back in engine compartment. Ensure the wheel-well behind the airbox does not block your intended position.
--After ensuring you have placed your mark in a "good" spot, recheck everything. Use the "Measure twice, cut once" methodology.
---I did not do that, and had to plug a hole in my airbox. This is why I'm stressing this part

-Drill hole for fitting. This is the fitting you will likely want to use. I used a straight version. Either works.
http://www.westmarine.com/webapp/wcs/st ... sNum=10638

--Place your hose fitting into hole, Tighten into place. If the fins on the side are preventing a flat seal, they twist out in small pieces with a pair of pliers. The adapter for the hose should be on the OUTSIDE of the airbox with the threads on the inside of the airbox - this is important.

-Reinstall and reassemble airbox. Leave the lid off.

-Attach your hose to the PCV fitting on engine top. Zip-tie tightly into place.
--Route to the airbox hose. DO NOT CUT hose yet!!!!!!!!!!!!

-It is important that you are able to make the connection to the airbox with no kinks in the hose. If you have kinks, it will not work correctly.
--Trim hose in small increments to get to non-kink length. Too long, and you will kink. Too short, and you won't be able to make the connection.
--When you have the correct length and hose fitted on the fitting nipple, firmly zip-tie into place.

-Use oil-absorbent material from a marine store like this:

(http://www.westmarine.com/webapp/wcs/st ... sNum=10441)

--Cut a small square out.
--Go to your hose fitting inside the airbox and wrap square of material around threads.
--Double zip-tie into place (two separate zip-ties)

-Lastly, Test run engine (Put oil cap back on engine BEFORE STARTING, or you will take a bath in oil mist). If successful, reassemble all parts. If you follow these directions, you will be successful.

The oil absorbent material on the inside of the airbox is critical. It knocks the oil out of suspension in the air coming from the PCV. Yes, you may have oil dripping from your airbox in time, but it is of little concern.

You have just rerouted your PCV fumes to still be burned (mostly) in the engine, while preventing oil-saturation in your air filter and in the intake side of the engine. Your total cost should be about $20-$30 USD. It still burns the "nasties" without oiling up everything.

After over 9,000 miles, I am still on the same air filter, and it is still looking pretty good.

bugnout · **Posted:** Thu Oct 07, 2010 1:45 pm

9000 miles is a good test. Can you take some pic's of your setup, especially the air filter after 9000 miles etc.

Thanks for posting.

4sefed · **Posted:** Thu Oct 07, 2010 11:57 pm

Yeah thats a fantastic idea...

Thanks for posting!
:pepper:

journeyjim · **Posted:** Tue Oct 19, 2010 9:13 pm

That is a great idea, I am getting a lot of bad looks from the vapor from the EHM. I was wondering though if a pvc filter that went inside the air filter housing on the carb vehicles we had thirty years ago, would work it would catch the oil vapor, it might need to be replaced a lot more often though since there is a lot of vapor coming thru that hose. :2cents:

Quiksilver · **Posted:** Mon Mar 28, 2011 9:37 am

bump - hows this running?

painemann · **Joined:** Sat Dec 20, 2008 7:02 pm **Posts:** 607

Still going good? I am considering doing this buy I'm worried about the ambient air temp in the freezing Michigan winter freezing the end in the air box!
Has anyone else done this yet?

ibHenry · **Posted:** Tue Sep 13, 2011 11:41 am

I made one modification, instead of buying the marine fitting I purchased a breather, it comes with the filter pad in it, (it was used on carbureted gasers in the 80's inside the air cleaner housing) for 3.00 that fits perfectly. Advance Discount auto parts has it under part number B23133. :grim:

http://shop.advanceautoparts.com/webapp ... ILTAMS____

METCRD · **Posted:** Wed Oct 12, 2011 6:43 pm

I really like the idea of sending the EHM to the airbox along with the absorbent material to knock the oil out of suspension. One thing that I will probably change when doing this mod is having the absorbent material seal off the entire bottom of the box to allow the greatest amount of surface area for the fumes to exit through. I am unsure how great of an difference if any this would make, but to me it seems like a good idea and may help the material not get clogged as quickly.

Tony P. · **Posted:** Mon Jan 02, 2012 6:40 pm

spitfire36o · **Posted:** Thu Feb 16, 2012 12:31 pm

ibHenry wrote:

I made one modification, instead of buying the marine fitting I purchased a breather, it comes with the filter pad in it, (it was used on carbureted gasers in the 80's inside the air cleaner housing) for 3.00 that fits perfectly. Advance Discount auto parts has it under part number B23133. :grim:

http://shop.advanceautoparts.com/webapp ... ILTAMS____

How long have the filters been lasting you before they are saturated with oil?

ibHenry · **Posted:** Thu Feb 16, 2012 11:13 pm

Tony P. wrote:

I did it this way at first too, I modded again and used a large pill bottle with some cotton in it, I'll post pictures in a few days. My air filter lasted 7000mi. with the first mod. :JEEPIN:

galatron · **Posted:** Fri Feb 24, 2012 1:41 pm

why not just take the ccv apart and put some cotton in it or wire meshing?

KJHooligan · **Joined:** Fri Mar 02, 2012 10:45 pm **Posts:** 30

Just thought I'd add my version of the mod. I ran the hose around to the front so I didn't even have to pull the airbox. I decided to mount the vent sideways so that the oil would drain, and I used an old plactic container to catch the oil. I figure with any luck I'll just pull the container and drain it at every oil change.

I had to drill the hole in the airbox big enough to barely slip the hose through. That way I was able to hook it to the vent and then pull it back so the hose was tight in the hole.

Sunazur · **Joined:** Mon Jan 03, 2011 6:18 pm **Posts:** 33

Hello dear Lost friends,
I was thinking to perform the modification, it seems very simple ..
I was thinking , such oily air in the air filter will not pollute prematurely the air filter itself and after ( even worst ! ) the MAF sensor :juggle:

?
MAF sensor is very delicate to handle and clean .. I do not think is very wise to inject the CCV output directly ( even with a small oil collector cap ) into ..

I was thinking therefore to plug this kind filter before eventually plug the ouput to the air box ...
http://www.ebay.com/itm/Universal-ALUMI ... es&vxp=mtr

( is just enough to look for "oil separator" keywords... ... )
( ok , is not a provent ... )
I think it will reduce the % oily air rate ....

What about this idea ??

KJHooligan · **Joined:** Fri Mar 02, 2012 10:45 pm **Posts:** 30

There are probably 100 ways to accomplish this, but you can be the test pilot with that one and let us know!

I can tell you I've put about 4k miles on mine now with my set up and the air filter looks fine. The breather element is working as intended because I just checked yesterday and I've got about a half inch of oil in the bottom of the catch can. I can't imagine any oil vapor getting through the air filter and damaging the maf sensor.

Tony P. · **Posted:** Thu Apr 12, 2012 11:06 pm

Update, re-moded the EHM to Airbox. Spun the breather around. The breather now emits the (fumes/oil mist) in a downward direction, towards the bottom of the airbox. The reason for this is because the air filter would become saturated with oil prematurely as well as past through the filter. Also plugged the two drain holes in the bottom of the airbox in an attempt to stop the jeep from dripping oil everywhere, just have to clean it out periodically.

racertracer · **Posted:** Tue Apr 17, 2012 6:54 am

I would like to make everyone aware of my experience with this modification.

After installing this modification my air filter became sooty with oil and clogged very quickly, within weeks, depriving the intake of the full amount of air flow it demands.

The oily residue built up on the air filter decreases the flow of air to the intake and according to the VM representative I spoke to, our engine cannot be deprived of ambient air, the more air the better especially when traveling on the open road for extended periods of time. Depriving the engine of ambient air will lead to overheating and possible head gasket failures.

This modification may work if it were installed after the air filter and before the turbo so that the paper filter does not get clooged with oily residue.

I am sure that the engineers at VM and Chrysler took this modification in consideration and decided against it for this reason.

But I wonder if this modification would work OK when used in conjuction with the K&N filter, since the K&N filter uses oil soaked filter media as part of its design already.

Tony P. · **Posted:** Tue Apr 17, 2012 10:05 pm

Racertracer first and foremost thank you for the information you posted. Sharing information in invaluable and what makes this a great forum. Next, I also read in one of your post about your crash glad to read that everyone was ok. I couldn't see the pictures though, can't remember why.

I have had this modification on the jeep for several thousands of miles periodically checking the air filter of-course, to date I am happy with the end result. I understand that the added air and oily soot will naturally prematurely clog the air filter. With regular checks and replacement of the air filter this modification should serve it's purpose eliminate oil/soot from the intake track extending the performance and life of the engine, as do several other different modifications like this these EHM, oil air seperator, etc...

I have regularly changed the air filter and noticed since the modification added gunk on the air filter which was/is expected. I will not allow the air filter to become so saturated/clogged as to deprive the engine of ambient air.

What failure did you experience with this modification? Was it a direct result of this modification? Are their others with similar failures with this modification?

xhizzous · **Posted:** Thu Apr 19, 2012 7:41 pm

Here is an idea...
I haven't had the time to extensively study the V6 airbox at all (still looking for one to install though) but does the V6 already have a CCV port in the airbox you can just use if you switch airboxes and use the bigger 6cyl filter+get better airflow anyways.

I currently have the EHM and its routed with 9 1/2 feet of vinyl tubing to just in front of the trailing arm for the rear drivers side axle.. and yes it does make a cloud sometimes. At least back there it minimizes the amount that comes into the vehicle if all the windows are down.

4wheeldeal · **Joined:** Thu Mar 15, 2012 11:11 pm **Posts:** 70

I've been into modded Hondas for about 14 years now and we normally use catch cans with turbos, works well, alot just vent it using alittle vent but MTO love to see that as its about a 300$ ticket.

I do like the venting to the air box, but it looks like some oil puddles in that picture.

A catch can will hold the build up and you can drain it once a year, still vented but just the fumes are vented.

EHM to Airbox Mod

Who is online