My old F250 has had a bit of a blowby problem as long as I've had it. Part of it is the actual quantity of blowby gases and at least part of it is probably due to the fact that with the Banks tubo kit, the CDR never sees much vacuum.

So, I decided it needed an oil trap. I decided to make the body of it out of 4" PVC and the body of the unit is threaded so that the bottom half screws off to allow you to dump the trapped oil back into the crank case. This removeable collection chamber has about a 1 quart capacity. I initially built the unit with 1/2" inlet and outlet tubes, and unfortunately, this resulted in excessive backpressure and the engine started puking oil out of the dipstick tube.

So I went back to the drawing board and enlarged the inlet and outlet tubes to 3/4". The original design included a 90 degree elbow inside on the inlet tube inside the main chamber to aim the vapor stream at the inside wall of the oil trap chamber. The idea was that the oil vapor colliding with the wall of the chamber would cause it to condense and then collect in the bottom of the chamber. While this resolved the backpressure issue, it didn't trap much oil.

So, I got rid of the inlet elbow that aimed the vapor stream towards the inside wall of the chamber and replaced it with a straight pipe that went down to within 1-1/2" of the bottom of the chamber. Then I got some very coarse steel wool (# 4 size) at the hardware store and stuffed a bunch of it into the upper part of the main body so that the oil vapor would have to pass through it to get to the outlet.

So far I've only driven it one day to work and back (about 50 miles). No backpressure issues or oil puking out of the dipstick tube. When I screwed off the collection chamber (after letting it sit overnight) and looked inside, LO AND BEHOLD! It had about 1/4" of oil in the bottom! At least 3 or 4 ounces.

In terms of how much it is trapping, the installation of this new design just HAPPENED to coincide with my failing an emmissions test. It blew a 59% on the opacity test without the oil trap (the limit is 55%) and failed. After installing the oil trap I ran it through again the next day and it blew a 43% on the opacity test and it PASSED!

Before installing the oil trap it was burning through a quart of oil every 200 miles or so. On a 50 mile trip that would be about 8 ounces. Since the trap had about half that much in it, and my exhaust opacity results were reduced by over 25%, it looks like this oil trap has reduced my oil consumption by around 50%. Since some of the oil consumption is undoubtedly oil getting into the cylinder past the rings and past the valve guide seals (which I'm convinced are shot) I think its pretty safe to say that the oil trap is catching nearly all the blowby oil that was going into the intake. Before it blew a big blue cloud of smoke every time I stepped on the throttle. Now it almost never blows any blue smoke and I can actually see the black smoke it makes when pulling hard!

Since my main concerns were the amount of oil vapor going through the turbo, and the fact that oil into the intake concentrates in the back two cylinders (causing them to overheat and develop head gasket leaks), I'm really happy with the results. I can handle it burning a quart every 300-500 miles as long as it isn't killing my turbo or eroding my headgaskets...

 

This info may be of value to you......Don is a Ford/Navistar specialist.

DieselDon

Oil consumption, and the proper checking of the oil levels in Ford diesels comes up periodically. Ford dipsticks are calibrated for hot oil. The 10 quarts in the IDI engines expand about 1/2 to 3/4 of a quart as the oil heats up, and contracts the same amout after cooling. If you check the oil first thing in the morning ( which I grew up doing ) the engines will all indicate oils level below full, but when checked hot, will ( after a 10 minute drain time ) the oil level is usually at full. If you are checking the oil cold, and keeping the level at full, you are actually over filling the engine which will burn of the extra rapidly.

Suggestion: Check oil hot after 10 minute drain time.
Don't add until level reaches add line ( 2 quarts ).

In my days at Ford this often cured, or at least improved, the apparent oil consumption complaints.

 

I had similar oil comsumption with my engine before the rebuild, and the valve seals were most certainly shot! Hard, brittle and they came off in pieces.

Not much of a consumption problem anymore, but your solution still sounds very interesting. Could you post some images of it? The more oil staying in the engine, the better.

Steel wool is whats used in the 6.5 valve cover baffle to reduce oil comsumption and that engine still has a CDR on it.

 

Thanks for posting the oil check procedure again PLC7.3 - I've seen it several times and am doing it the right way.

I plan on taking some pictures and posting them here sometime in the next few days. Just to be clear, I still have my CDR installed. The oil trap is just installed between the breather tube and the CDR so that very little oil vapor ever makes it to the CDR.

Some of you may remember I did an experiment where I relocated my CDR to the OUTSIDE of my filter - which is a K&N oiled filter that came with the Banks. The idea was that the filter would trap the oil, and since it is an oiled filter anyway, it wouldn't hurt it any.

This idea worked well for about 100-200 miles - until the filter became oil saturated. Then the excess started getting past the filter and right into the intake again. If anything relocating the CDR actually made the oil consumption worse because since there is NO vacuum on the outside of the filter, the CDR never closed at all. With the CDR venting to the INSIDE of the filter there is at least SOME vacuum being applied to it to close it (at least partially) at higher RPMs.

So, now my CDR is back to its original location venting to the inside of the the filter - between the filter and the turbo inlet. With the trap catching most of the oil things are working much better now...

Anybody ever replace the valve seals on one of these without pulling the heads? Is it even possible, and if so, how hard was it? Will a regular overhead spring compressor handle the valve springs on these engines, or (like everything else about them) are the valve springs so heavy duty they take a special tool?

 

An off the shelf valve spring compressor will do, just make sure you bring each piston to TDC in the cylinder you are working on before removing the valve keepers on that cylinder.

This is what I got. Its made under many different brands so shop around for the best price. https://www.northerntool.com/images/...094279_med.gif

I've noticed a difference in oil level between hot and cold, but the difference is usually within 1qt. Before the new seals, there was certainly a difference in consumption between filling to the top cold, and letting it sit at the 1/4 mark hot. Its at about the 1/3 mark right now and hasn't moved since the last oil change.

 

I checked about half my valves that way, before deciding to pull heads and have rebuilt. Just like dave said, make sure piston is at tdc for cyl. Also, I noticed about a 3/8" movement on the valves with head at tdc. so there's more room there(clearance) than I've read here.

 

The book I have here does not list the valve lift.
But when you have about .375 movement from closed to against the piston, there is not much valve clearance.

 

Sounds to me like it was not at TDC, but still close to it. The valves are nearly flush with the deck of the head in the closed position and the pistons actually protrude above the deck on the block by 30 thou according to some sources. Mine were 10 above after 20 thou taken off of them when I installed them so that seems to agree. Basically, the only clearance is the head gasket and even then, some of that is taken up.

 

Thanks for the feedback David85 - I actually already have one of those tools and have used it a couple of times. Getting each cylinder to TDC is definitely an important step if you want to avoid having to pull a head due to loosing a valve into the cylinder. The good news is that there are at least 2 cylinders at a time at TDC (1 on exhaust and 1 on intake).

Anyways, as promised here are a few pictures of what I built.

Inlet pipe


Outlet pipe


Separating the two halves


Upper assembly


Steel wool in upper assembly


Lower assembly - with trapped oil


Hose routing from fill neck


Location of installed trap


You'll note the red grease on the threads where the bottom catch-can screws off. It helps prevent any oil from blowing up and out past the threads as well as keeping them lubed so that it screws off easily for emptying...

 

Looks like a neat little gizmo. Only problem is you would have to take the bottom off to recover the oil. I would be a little concerned about fragments of that steel wool getting in there, but if its course it should hold up fairly well. Maybe make a metal baffle with some holes to hold it in place if you run into that problem.

So basically you just drain that every few hundred miles to make up for the lost oil? cool idea.

Getting the pistons to TDC isn't that hard. Just turn it over until you are as close as you think you can get and and push down on the valve by hand to see how much space there is. I would expect less than 1/8" if it is really at the top. Turn the engine one way or another to get it as close as you can. This way theres no worry at all of loosing the valve in the cylinder and you will want it as high as possible in the guide to get the keepers out (psiton will hold it up).

Why is your AC disconnected?

 

Yeah, I thought about the issue of small pieces of steel wool breaking off and gettinginto the oil too. I figure dropping a strong magnet into the bottom of the catch can ought to take care of any pieces that break free.

I'm really not sure why the AC is disconnected. It was like that when I got the truck. It may be easily repairable, or it may be toast. I really don't know because I haven't had time to dig into it. It doesn't get that hot for that long in my area, so it hasn't been a very high priority for me...

 

That is a lot like I was thinking about, but I had the pipes in a little different location.

Inlet at the bottom with the unit located higher than the motor.

That way any oil collected could drain back in the engine when it was off.

A layer of one of those synthetic pot scrubbers located below the steel wool should keep the stray fragments inside the trap, but you would have to check to make sure it would hold up to the heat.

 

I thought about that, but I was aftaid that with the pressure coming in at the bottom it would cause the oil to bubble and splash so much it would saturate the steel wool and cause more oil to get past it. Maybe if the inlet was about a half inch to an inch above the bottom of the catch-can enough of the inlet would stay above the condensed oil to not splash so much and stll allow it to drain back once it got deep enough.

Again, I considered something like that, but was afraid it would saturate and possibly cause backpressure and oil puking out the dipstick tube again.

I may redesign it again to put the inlet on the side down low. I'd really like to figure out a way to make it significantly smaller. Maybe I can make the next one out of 3" PVC and make it only about 2/3 as tall. If I do that I won't even need to make it screw apart in the middle and I can install an internal magnet and line the bottom half it with steel window screen to prevent any steel wool fragments from getting out of the inlet/drain tube.

BTW, I ordered some more AutoRx today. I ordered THREE bottles this time. One to put in now and run for the rest of this oil change (to replace what's been burned off and diluted by adding oil) and two more for a second "treatment" application - after I do another oil change and complete the recommended 3000 mile "rinse/flush" cycle in between treatments...

 

Why are you so worried about the oil that has gathered in the bottom of the container? Your truck shouldnt have that much blow by. If your worried about the metal fragments being in the oil, go to a Detroit Diesel or Mack truck dealer and ask for the blow by filter in the Series 60 Detroit or the same for a mack Vision. They are capable of handling the heat from the blowby. I have to admit......That is a GREAT idea for keeping all the blow by oil off the underside of the truck tho. !!!!!!!!
Lets see......You say youd like to use the oil again from the container right? Why dont you make your inlet about 3 inches down from the top, put your filter in there above and below it so your oil is filtered going back in, and run your original vent tube straight out the top? That way its filtered going back in the engine, and it still has a block to keep oil from exiting out the vent, but its still able to breath. I would also recommend cleaning the filters between oil changes to see how its gonna do before you do any hard to the engine.
Thanks for listening! I work on diesels day in and out. Id like to find a way to do this on the big diesels!