I have a 1993 f150 xlt with a 351w. Everything was bone stock when I got it and only 147xxx miles on it. When I went to change the air filter about a year ago I noticed that there was a few drops of oil in the airbox and the air filter and breather filter were soaked with oil I changed the filters, cleaned the airbox and the crankcase vent tube and I thought it was fine for a couple of months, until I noticed it was still filling up with oil I looked online and bought a cheap oil catch can from amazon.com and installed it in line with the CCV tube. It kept the airbox clean, but I noticed that there was water and milky oil in the can. i tried to stop some of the liquid from entering the airbox by putting a 3/8 fuel filter in between the oil catch can and airbox. I decided to try and find the culprit responsible for this problem, so I looked around the engine and found that there was some coolant sitting on the engine next to the waterpump, and the thermostat housing was wet around the gasket. I replaced the housing, thermostat and gasket and also added some RTV gasket maker. the leak was stopped at the housing but there is now a few drops of coolant on the water pump gasket every time I drive and there is still milky oil coming out of the CCV tube. Does anyone have any suggestions or ideas on how to fix this?

 

My oil catch can setup



CCV tube on the oil filler neck





CCV tube where it enters the airbox



coolant in the bottom right hand corner of the photo

 

Sounds like to start with you need a new pcv valve,the easiest place for the crank case pressure to go now is the air filter box.

loosen the oil cap and start the motor and see if it pushes the cap off. you might have excessive blow-by.

As for the water do you see any in the oil?

 

I tried replacing the PCV valve with a Microgard PCV valve from O'Reilly's and it ended up forcing oil out of the dipstick tube (I read that these trucks only like to use Motorcraft PCVs )so I put the old one back in for now and it fixed that problem, but I will put a new one in when I find one. I havent seen any water in the oil or on the dipstick, just in the oil catch can. I will try the oil cap thing soon and see if it works.

 

When replacing the PVC valve you should ALWAYS check that there is vacuum on the hose going to the valve.. If there isn't the port in the intake is probably clogged...

 

Most likely either a hole in a piston, or more likely rings are worn and letting oil pass. This is exactly how I found out that I had a hole in a piston, lots of oil coming up that tube, fluid being forced out of the engine where they shouldn't.

 

+1 on this. I have seen a couple of Windsor motors with this issue - the port coming off the back of the manifold is plugged with carbon.

 

is this the upper or lower hose on the Pcv valve that goes to the manifold?

 

Cold weather ..........short trips........could be just condensation making it milky. X2 on replacing the PCV and checking that the port isn't clogged.

 

On a Windsor there is only 1 hose that goes from the manifold to the PCV that I am aware of. I have only seen the 2nd hose on the PCV on the 460.

However, the hose is irrelevant. The hose is not what is getting plugged up, it is the metal port that is screwed into the back of the upper manifold plenum that is at fault.

 

Here' my take on it & You can take it for what its worth.

On my 94, the vacuum/pcv set up is reversed from what you have. The Vac tree is to the rear & has ALL the vac lines including the brake booster line & the MAP sensor line (which appears to be by its self) go to it with the PVC going to a single nipple in the front.

I figure Ford had a reason for this change.

Also, I would check the hose that runs diagonally & around the back to the PCV valve for obstruction.

*** Check that, I don't see WHERE your PCV line enters the upper intake???

 

I didnt check this tube that goes to the right but I cleaned out the lower hose that had a bunch of oil and gunk inside and out



The bottom hose goes into the lower intake

 

The upper nipple needs to be capped, at least the one on mine was (if yours is open).

But I still wonder if the vacuum is higher on the upper chamber of the intake.

 

***UPDATE***
I was not able to get the PCV port off of the intake, but the water has stopped coming out of the CCV tube. My guess is that any coolant that was still in the oil evaporated after I replaced the water outlet.
Thanks for everyone's help

 

If this is open, you may have a vacuum leak & there is not enough draw of crankcase vapors back into the intake.