Hi all,

I bought a 92' 7.3idi(manual trans.) F-350 4x4 back in late September; after I bought it, I found this forum, and the 'read before purchasing thread', lol.

Any how, I felt somewhat comfortable when I bought the truck, as there seemed to be a fairly extensive maintenance log that came with it; most of the log contained verifiable receipts.

The truck has 228,000 miles on it, but has had quite a bit of work done to it. The engine was replaced with a re manufactured diesel at 150k; this was done due to a cavitation hole in one of the rear cylinders.

The records along with the fact the truck doesn't smoke at all; even under load, I figured it was a good engine. It starts on a dime, and runs strong.

However, when I bought it, the radiator was low, and it appeared that the thermostat wasn't working, as the truck didn't heat up.

Well, the other day, I finally got around to replacing the thermostat; I noticed the drain on the radiator was a bit plugged up, and went ahead and pulled the radiator. I took it to a radiator shop, and they rodded it out, and gave it a clean bill of health. They said it was about 35% clogged.

I asked with what, and they said it looked to be just old antifreeze, but could've also been some sort of stop leak; they weren't sure. At this point with the amount of work put into pulling the thing apart, I figured I'd get rid of a couple nagging oil leaks.

One oil leak was the mechanical fuel pump, the other was the Oil cooler. I pulled it today. Since I've owned the truck, it would leak a puddle the size of a silver dollar every night; not much, but enough to be annoying.

When I got the cooler out, it had a decent 1/4 inch of caked on old oil; it wouldn't simply wipe off, but took several rounds of cleaner.

So here's where I'm worried, on this forum, and several others, I've read that coolers with bad o-rings will almost fall apart; mine took quite a bit of rubber mallet blows before separating. The o-rings didn't look bad; one of the larger set had a cut through half of it; which I think would explain the oil leaking from the unit.

However, where I'm concerned is that when I drained the oil, which I've run for the last couple hundred miles, it had water in it.... I'm aware the cooler can cause this, but the smaller o-rings that I believe seal the water from the oil, didn't seem bad.

Due to this, I took the oil cooler to the local diesel shop/mechanic. In talking to him, he also didn't think those o-rings looked bad. I decided to leave the new o rings, and cooler for him to clean test, and reassemble.

So the cooler was leaking oil, but I don't know that it's the cause of the water in the oil.... Of note, the frame rail by the cooler, on the outside has a bit of 'white' on it, which would appear to possibly be from water? Yet, and if so, I don't see how it came from the cooler unless it has a hole, or the gasket that failed was the between the header, and block.

I know this is a long post already, but can anyone give me any ideas to check on, or any input into head gasket failures? Is it possible that only the part of the headgasket that failed would be between only the water, and oil jackets?

There's no white smoke, and no bubbling in the radiator.

Sorry for the long diatribe, and on that note, I want to thank all of you all here for the cumulative knowledge. It's got me through quite a bit of body work, and actually quite a bit on the truck in general.

Thank You,

Joe

 

If You have water in the oil it could be the Gasket on the hood leaking rain water onto the engine and then the water leaks into the engine through the grommet on the valley pan for the crankcase breather valve. If you have coolant in the oil it could be a leak at the water pump to timing gear cover area that will put coolant in the pan without smoking or leaking on the ground.. you should do a cooling system pressure test with the glow plugs out and then have someone crank the engine over to see if water spays out of one of the cylinders. If it comes out the glow plug hole its a head crack or head gasket. If it leaks down pressure without showing up in one of the cylinders its most likely a pump leak.

 

I'd never considered anything like above even possible. It gives me pause for thought for sure! I'm fairly confident, and at least to a small degree happy that I don't have to cross that bridge, as I'm in Phoenix, Az, and under a carport; the truck doesn't get any rain.



Okay, I hate that there's another candidate for this engine besides the cooler, and head gasket, but this is some good food for thought.

In regards to the waterpump, it doesn't appear that anyone's been messing with it in a while; it sounds like the waterpump issue would be more with improper installation, than wear, and tear. Is that correct, or can wear, and tear cause what you described?

The diesel mechanic should have the oil cooler back together, and tested by tomorrow afternoon; I'll update after that, and once I try the engine out.

The part that really bothers me, and I seriously hope there's a fix for it, and that someone can direct me to it, is that at each step of this operation, and diagnosis, the coolant will continually be ruined with oil, or the oil ruined with coolant; until fixed.

 

If you have oil and coolant mixing you have started in the right place with the Oil Cooler... After its reinstalled and the cooling system has been stabilized you can watch the coolant level and you will have your answer soon enough.

 

I got it back together, and no mixing; problem solved with the cooler. I'm glad I took the cooler to the diesel mechanic, and had them assemble, and pressure check it; I can only imagine how crappy it'd been to put it back together, only to leak due to not getting the o-rings right.

On that note, I ran three rounds of distilled water, and soap through the system, before draining, and adding antifreeze.

Now onto other issues, such as clutch pivot arm, steering column, and high idle issues.