I have a 1987 F350 with the 6.9 in it. I noticed that the radiator has oil in it. The oil cooler is leaking oil and a little anti freeze. is it possible that they are mixing in the cooler. It hasnt lost any antifreeze and very little oil. It hasnt overheated either and i drive it 200 miles a week atleast. It has a bad miss and puts out a lot of white smoke. I have replaced injectors and glow plugs. it runs a little better and starts up great. I cant figure it out or afford any more guessing games. Can anyone help me?

 

What I would do is first find the missing cylinder. Try using your favorite 5/8 wrench and while the engine is running crack open the injector lines on top of the injectors. You should notice a drop in rpm and the engine sound should change with the line opened about 1/4 turn. If no change than that's the problematic cylinder.
In my case about a month ago I had 2 dead cylinders on the front passenger side. After compression check I was able to confirm blown head gasket. Turned out I pulled the motor to do the job and noticed the driver side head gasket was also almost blown out.

 

My first guess would be the oil cooler O rings need replaced.

About 50 dollars for parts at Ford.

White smoke can be an air leak in the fuel system, a dribbling injector, or a blown head gasket.
First check there is what does the white smoke smell like?
Sickenly sweet, antifreeze burning points to a blown head gasket.
Fuel smell, either air intrusion or dribbling injector.

Since there are oil drains in the head, it is possible for coolant to get in the oil from a blown head gasket.
But oil into the coolant is much less likely since the oil drains are not under pressure and the cooling system is.

 

The smoke smells like really rich fuel. There was no antifreeze in the oil but there is oil in the radiator. It doesnt seem to be losing either oil or antifreeze though. i bought the truck in february and havent added antifreeze. I changed the oil in april and hasnt seemed to go down much

 

Very possible the oil cooler failed, someone replaced the O rings in the oil cooler and never cleaned the cooling system out good.

 

A leaking oring on the oil cooler won't give you a miss or raw fuel at the tail pipe.
Still think there is another issue such as bad valve or blown head gasket or even bad injector. Do your self a favor and do a compression check and open the injectors to see what cylinder(s) is missing like I described in a past post.

 

The injectors are new just replaced last week but the problem continued. Is it possible the return lines are allowing air in. i also heard the timing being off could cause this. I tried cracking the lines like you said and it runs worse on each cylinder so that didnt help. i dont think it is a head gasket im not losing any fluids and it doesnt over heat like other vehicles ive seen with blown head gaskets.

 

How do i check for a bad valve?

 

Can you do a compression check? Some guys picked up a diesel compression tester from Harbor freight for cheap. Test all 8 cylinder by unplugging the fuel shut off solinoid on the top of the injection pump. FYI my head gasket failure had no signs of oil or water loss because it blew out the fire ring and was passing compression from cylinder to cylinder. Easily detected with compression check. I also had a bad miss and raw fuel and I
could hear huffing back through the intake.

 

Again with your compression tester, you can put th cylinder you want to test @ top dead center on compression stroke and put air pressure into the cylinder via the glow plug hole and listen/feel for air leaks.
Just be careful because the air could cause the engine to turn over.

 

Better yet, if you can put shop air into the cylinder, loosen all the rockers so the valves stay closed and remove the radiator cap.
Remove all of the glow plugs.

When you apply air to the cylinder, the piston goes to BDC and you test everything in that cylinder.
Cavitation or blown head gasket will push coolant out of the radiator.
Blown head gasket may let air out of an adjoining glow plug hole.
Leaking valves let air exit the intake or exhaust.
Broken or stuck rings let a lot of air into the crankcase.

When you know exactly what cylinder the problem is in, it makes it much easier to find when you tear the engine down.