Oil in my Radiator!!! -- Please Help

tomdt · 03-18-2011, 12:09 PM

Does anybody know what can cause engine oil in the radiator coolant?

Three months ago, I purchased a 1993 Ford E250, 5.4L SMB with 65K miles. Before buying it, I had a reputable mechanic check it out and he noted that the antifreeze for dirty (but no mention of oil). After I bought it and drove it 500 miles of so, I had the antifreeze changed, and the mechanic assures me there was no oil in the antifreeze at that time.

I recently had a small coolant leak, and the mechanic had to remove the upper radiator hose to get to the leak. When he did, he notice that there was motor oil lining the hose. Further inspection showed black motor oil floating in the radiator and overflow tank. This has only gotten worse over the last couple months.

It is clearly motor oil (and not tranny fluid) and will eventually eat up my radiator hoses. The mechanic assures me that it is not a blown head gasket because a) the valves/rockes are lubricated by splash so pressurized oil does not pass through the head gasket and b) there are no hydrocarbon gasses in the antifreeze.

The mechanic's conclusion, by process of elimination, is a cracked block which requires replacement of the whole engine. Well, that is possible, but the Ford 5.4 L engines are not known of that type of problem. I'd really hate to replace the engine, only to find that that was not the cause of the problem.

Any thoughts or suggestions would be appreciated. Thanks.

woodbee · 03-18-2011, 02:56 PM

I believe if it was a cracked block you would have coolant in your engine oil.

Woody

tomdt · 03-18-2011, 03:12 PM

Quote:

Originally Posted by woodbee

I believe if it was a cracked block you would have coolant in your engine oil.

Woody

Thanks Woody. I asked that exact qustion. No water in the oil (or at least I hope not, God forbid). My understanding is that the oil pressure is much higher than the water pressure, thus oil is forced through the crack (if it exists) into the coolant rather than coolant into the oil. Your reaction?

Silver350 · 03-18-2011, 03:59 PM

Well, so far the process of deduction has an engine that first came out in late 1997, in a 1993 van, and a cracked block diagnosed by a mechanic that wants to replace the engine without further investigation.

Is it possible that there is residue left over from a previous repair? If it was me, since you have a very short history with this vehicle, I would change the oil immediately just in case there is coolant in it. Flush the cooling system using a cleaner, then take oil and coolant samples after some driving.

tomdt · 03-18-2011, 04:26 PM

Quote:

Originally Posted by Silver350

Well, so far the process of deduction has an engine that first came out in late 1997, in a 1993 van, and a cracked block diagnosed by a mechanic that wants to replace the engine without further investigation.

Is it possible that there is residue left over from a previous repair? If it was me, since you have a very short history with this vehicle, I would change the oil immediately just in case there is coolant in it. Flush the cooling system using a cleaner, then take oil and coolant samples after some driving.

Thanks for the thoughts. Maybe I grabbed the wrong engine description, sorry. It is the 351 cubic inch fuel injected V-8, original 1993 stock engine.

We have changed the oil and checked the oil to confirm no coolant (luckily the water settles to the bottom of the oil pan). I when I first purchased the vehicle, two independent mechanics verified there was no oil in the coolant. The quanitity of oil floating in the coolant is unquestionably increasing every time I drive the vehicle.

There is probably no downside to draining the antifreeze, flushing the system, and refilling it with plain water (no risk of freezing here in San Diego) before we replace the engine. Stranger things have happened, but I doubt that is the solution. If it is, I'll buy you a nice dinner :-)

I stongly agree with your point on "replacing the engine without further diagnosis", but not sure what additional diagnosis I can ask for. The oil pressure is fine, so there is no major leak. I suppose we could check compression on each cylider, but I doubt that would tell us much. The inability to see what is going on is very frustrating to me.

Silver350 · 03-18-2011, 08:00 PM

I'm not sure why you are so quick to rule out a head gasket. The only way to tell for sure if there is coolant in your oil is through oil analysis, its a cheap test (+/-$25) and will tell you so much. Before you spend big money on this, try some "Irontite". I once used it to seal up an old 400 Cummins for 100,000 miles before I finally rebuilt it. It really works.

tomdt · 03-18-2011, 08:41 PM

Quote:

Originally Posted by Silver350

I'm not sure why you are so quick to rule out a head gasket. The only way to tell for sure if there is coolant in your oil is through oil analysis, its a cheap test (+/-$25) and will tell you so much. Before you spend big money on this, try some "Irontite". I once used it to seal up an old 400 Cummins for 100,000 miles before I finally rebuilt it. It really works.

Wow, again, thanks for all the thoughts. The primary reason for ruling out the head gasket is that the scematic for this engine apparently does not show any pressurized oil channels passing throught the head gasket. Instead, according to my mechanic, it shows that the rocker arm assembly, push rod, etc are all splash lubricated.

I will definately do the oil analysis. Oil in the coolant is a concern. Water in the oil is a potential disaster.

Finally, I will do some research on Irontite. Thanks for the the info.

Silver350 · 03-19-2011, 04:53 AM

OK. The top end is splash lubricated, but how does the oil get to the top? It is either through an external oil line or through the inside, through a head gasket.

Ford_6L_E350 · 03-19-2011, 10:30 AM

Quote:

Originally Posted by Silver350

OK. The top end is splash lubricated, but how does the oil get to the top? It is either through an external oil line or through the inside, through a head gasket.

Or, up throught the pushrods. Common in many older engine designs. Not sure about this one.

Mike

tomdt · 03-19-2011, 12:49 PM

Quote:

Originally Posted by Ford_6L_E350

Quote:

Originally Posted by Silver350

OK. The top end is splash lubricated, but how does the oil get to the top? It is either through an external oil line or through the inside, through a head gasket.

Or, up throught the pushrods. Common in many older engine designs. Not sure about this one.

Mike

Not sure how oil is getting to rocker/push/valve assembly in this engine. My mechanic tells me no presurized oil throught the head, and I think I need to trust him on that (or at least until I have information to the contrary).

Back to the bigger questions:

1. Any thing else that can cause oil in the coolant besides a) cracked block, b) blown head gasket or c) someone pouring oil in the radiator?

2. What do people think about Irontite or a similar product? Frankly, if we cannot identify any option other than a cracked block (or possibly a blown head gasket), I don't see a downside to trying it, flushing the radiator and see if we get more oil in the coolant.