Hi guys, I have been noticing synthetic mobil one in my coolant, its hard to tell how much exactly but there is a film of oil in there. I was wondering if the oil coolers are prone to leak that way, or am I looking at something far more serious. Its definately motor oil and not tranny fluid. My van has always used about a quart between changes since new. The oil has accumulated over 150,000 miles like a scum in the tank and so I thought I would ask what you guys have heard about this problem
Andrew.

 

If you see engine oil in the radiator tank, it got there from the head, unless you have an SD with an oil cooler, and not just the standard transmission heat exchanger. If it were leaking, it would be ATF and your tyranny would be low.
It could be a head gasket or cracked head, do you see any coolant in the oil?
Most repair shops can test the radiator for exhaust gas, that's a sign of a bad head gasket, or cracked head.
Good Luck.

 

yeah my fear would be headgasket aswell..

 

Mine is a superduty and I thought that there was some kind of oil cooler on that v10 near the oil filter or tied in with that setup. Is that true? and did they have trouble with them leaking?
I heard something about a manifold bolt that would cause some similar symptoms or oil in the coolant, do you know anything about these issues.
I have not found any water in the oil.
thanks for the replies,
Andrew.

 

Andrew, Yes if its an SD it most likely does have an oil cooler, my 01 E-450 SD does, and part its located at the oil filter, and two hoses run forward to the radiator tank.
I have not heard of even one leaking, and I know if it is leaking, its not a common problem.
You could have a shop check the radiator for exhaust gas, for vary little money, and start there in tracing it down.
A weeping head gasket is much better than a cracked head.
I have heard about head bolts cut to allow the passage of oil, but not on this engine to my knowledge, but its possible, someone else will answer that question.
Good Luck.

 

Most likely the oil cooler.

They rot through if you don't take VERY good care of the coolant. High oil pressure will overcome the low pressure in the cooling system. Eventually though, you might wind up with coolant flowing back into the oil, so you better do something about it right away.

Replacing the cooler is probably the only thing to do - PM FTE/PARTS-GUY for a price, or go to y2kford.com and click on Parts/Order Parts for pricing.

 

This begs the question.
You have changed the fluid out over 150000 miles of Engine life ? - Yes
Annually - Yes.
Anti corrosive properties fade over time.

 

I like this theory!
The symptoms of oil in the water but no (reported) water in the oil was causing me to scratch my head. To have this happen, the oil had to be under higher pressure than the water at the point of crossover leakage. Since coolant is around 15psi throughout the entire system, the leak had to be in an area where oil is over 15 psi. Not that many areas.
Of course, in the modular engines there does need to be a high pressure block to head passage somewhere due to the need to lube the cams so the head gasket is still a possiblility....

 

mwsF250 that is exactly what I was thinking. the oil pressure is exceeding the water pressure at some point. I thought this would be happening in the oil cooler, what kind of pressure would be in that thing?
I have changed my coolant at Ford recommended intervals with the factory fluid doing around 100,000 in three years, and the last 45k I ran Prestone extended then changed it this year and now have 5,000 on it.
The van runs perfect, I have not had any overheating issues or water loss, nor is there any water in the oil.
today I cleaned the plastic coolant tank and its not a lot of oil but it did coat the inside of the tank. The other thing is that this must have been going on quite a while because the coolant container changed color and got darker two years ago and I never thought it would be oil in there. It was only yesterday that I put my finger in there and realized it was motor oil scum.
I went to the Ford place today and talked with a pretty knowlegable mechanic who was working on a v10 and had the whole front off the van pulling the motor. He showed me the radiator hose connection to the block and said that there is a gasket there that cracks between the block and the spout and that will let oil into the coolant. I got home and looked at mine but mine may not have the oil cooler, above my oil filter isn't finned for cooling like the one on the bus was. I looked in the workshop manual but they have no picture of the V10 where the hose connects to the block to show me if there is some feed there for oil and coolant to get mixed up in the event of the gasket failing. He didn't point to the cooler, but to the alloy piece the hose connects to. Apparently the gasket behind that cracks with age and I might go back tomorrow now that I have looked at mine and see if he thinks its true of my set up too.
I appreciate all the input guys. I will get to the bottom of this and hopefully its the little gasket and not big one upstairs that is the problem.
I will let you know. The hose is the bottom radiator hose connect point not the top.
Andrew.

 

I went out and looked at my van and it appears the way the oil cooler setup works that there is oil coming out of the motor to go into the oil filter and there is water also coming out of the motor, or going into the motor through the same gasket. The mechanic told me that he has seen it happen before so there must be some Ford comment on it somewhere I would think.
The engine mount has to come off and the whole filter holding assembly but that is nothing compared to a headgasket job. I will try replacing this gasket first.
Andrew.

 

While you have the cooler off, get it pressure/vacuum checked. Just to be safe.

 

The oil cooler on my F250 is just an aluminum "blob" between the block and filter with the two coolant lines going to it.
On the V10 I pulled from a Class A motorhome, the oil cooler is bigger with pretty fins on it.
So it sounds like there are at least two versions, the extra sized one you saw on the van and the standard duty, which you may still have on yours.

Good luck! That would be an easy fix!

 

On my Class C Motor Home, is the standard "Blob unit, if you will" just a block of aluminum. But this is the factory Ford part, on the Class A it must be an after market unit.
It doesnt take much oil in the coolant to look bad in the expansion tank, as the oil floats on top of the coolant, and the tank is connected to the top of the radiator tank. Not that this helps much. But it should be a relatively easy fix.
Good Luck.

 

Well I went to another Ford dealer today who had the gasket for the oil cooler in stock and he told me that he sold two yesterday. He says those gaskets leak often and he sees this issue all the time. I asked about buying the whole cooler set up in case I had a leaking cooler and he said he has not seen a bad cooler yet, so I am going to replace the gasket and see if that is the fix for $9. The cooler is $270.
Yes there are several different oil coolers, the bigger applications for the
V10 like 20 passenger bus etc use the finned one and the one that is on my 15 passenger van E350 SRW is not finned but a cooler for sure. It seems in dual rear wheel applications they wanted a bit more oil cooling.
I don't believe the oil in the coolant will do any harm, but I would hate to think that neglecting that would cause water to get in my oil at some point, so I will fix it tomorrow and let you know how it goes. The motor mount will have to be loosened off the motor at least and I might be able to squeeze the gasket, which is a very nice looking gasket, out of place and slide the new one in.
thanks for the input guys
Andrew.

 

I can tell you that on my 2001 E-450 SD V-10 its oil cooler is the standard aluminum block unit, now maybe on the F 550 SD they use the bigger unit, but my E-450 has a GVWR of 14,050 lbs, as big as the Van's chassis get, except for the 08s that the GVWR went up by 500 lbs, there were to many overloads I guess.
I wonder if tightening the two bolts from time to time will help, the aluminum must expand faster or more than the cast iron block, and maybe that's why they can start to leak across. Just a guess.
So let us know what the old gasket looks like, and if you find out anything, and how big a job it is.