Antifreeze in oil pan

[R&B]

I have a FE428 and I just went to pull my oil pan and noticed about 1 qt. of antifreeze in the oil pan. I had the engine rebuilt about two years ago (new aluminum heads) but due to some delays did not get it into the car and started until a few months ago. I changed the oil after the initial 30 minute break in period and did not notice antifreeze in the oil then. The temp never went above ~215f.

I have been working on the radiator and heater and wondering if there could have been any other way to get water in the oil? Or should I just stop dreaming and check the head gaskets?

[aumoore]

I think there is a leak down test you can have preformed??

[chopper]

IMHO, you should check the head gaskets, this is the most probable source of the leak. As far as I know, the other common way to get fluid transfer between the cooling and lubrication systems is via a crack in the block or one of the cylinder heads. The only other possibility I can think of is if you are using some sort of heat exchanger that uses an automatic transmission-type cooler imbedded in the main radiator to cool the engine oil. That's pretty uncommon, but if you are, you might check that heat exchanger for a rupture.

When the builder rebuilt your engine, did they check the mating surface between the block and heads to ensure they were parallel? If the mating surfaces don't match properly, the gasket may not have been able to compress properly and this will certainly make it susceptible to a relatively quick failure.

Do you have any idea how long it ran with the coolant in the oil pan? If you think it was a while, you might also check the bearings while you have the pan off to make sure you didn't damage any of them due to oil dilution.

By the way, not trying to muddy the waters, but your aluminum heads weren't made by Dove, were they? If so, the possibility of a transfer via the heads may be a bit higher than otherwise. See the thread:

Dove Performance sucks

earlier in the FE forum. Hopefully, though, it's just a gasket.

If all else fails, you might give the folks at Southern Automotive (right down the road from you in McDonough) a call. Bill or Louis might be able to offer some other suggestions. Keep us informed.

[Back in Black]

Likely your heads are warped/loose/cracked. Check torque specs and procedure first, if it's loose, that is likely your problem. IF they are loose, then: Do not run it much at all, before you drain the new oil and check for more antifreeze!
If they are correctly torqued, it's warped (more likely with aluminum heads) or cracked (more likely with cast iron) heads.
It could also be a cracked block !

[Mr.Fixit]

If your heads were made by dove, they could just be seeping water through them. Otherwise, a cracked block or head; or a bad head gasket.

[hound dog]

I'd say the most likely cause is a "simple" head gasket failure. Did you re-torque the head bolts after the engine was run for a couple of hours? Most of the aluminum head manufacturers will recommend a re-torqueing. This could contribute to the gaskets failing if you didn't.
h dog

[ERA535]

I am an optimist!!!

I would check to intake manifold gaskets first......you have to remove this intake to get the heads off anyway, so....

Good luck!

Pat

[dkjos]

Based on what I learned at that high-tuition school (Experience University - Class of '87), your bearings are probably not long for this world. Approximately 10 minutes running with anti-freeze in the oil resulted in bearing failure about 4,000 miles later. Tear-down also revealed significant cylinder wall scoring.

I hope your result is better than mine was!

[SFfiredog]

I'm with Pat as well. You may simply have an intake gasket problem.
Pull the valve covers
Drain the oil
Top off the radiator with water
Use a pressure tester to pressurize the cooling system to 14 to 16 lbs.
By looking through the holes and passageways between the head and manifold you should be able to see the 4 corners to the head to manifold.
See if you lose pressure on the tester.
If you do, look in the corners for water leakage.
Also, it is possible if you are using an old manifold some electrolysis may have created a pinhole in the manifold somewhere. I had the same thing happen inside the thermostat area of an old intake.
What type of heads, manifold, and gaskets are you using?
--Mike

[R&B]

Thanks for all of the help. I had rebuilt this engine once myself when it was in a different Ford, but when I put it in the Cobra I had someone who knew what he was doing rebuild the engine for me. He added an Edelbrock intake manifold and heads. I am not sure what gaskets he used. Unfortunately, for both of us, he died before I put the engine in the car and started it up.

I did not realize I had to re-torque the aluminum heads after the engine was started. I also did not realize that the manifold gasket could cause this problem. I checked a few of the rod bearings while I had the oil pan off and they looked almost brand new (the engine only has a couple of hours on it).

I think I will re-torque the head bolts and then try the pressure test first.

One other thought, I had a lot of problems with my expansion tank leaking, could I have gotten antifreeze in the oil somehow that way? My distributor seal looks good or I would have thought it could have gotten in that way.

[chopper]

I think it's highly unlikely that the main problem had anything to do with the expansion tank leak. The tank leak should have just blown coolant out through the rupture (at least, that's what mine did). It should also be unrelated to the distributor seal. Your planned course of action is logical IF you have found some of the head bolts loose. Then it would make sense that there may be a leak around one of the gaskets and the problem may be resolved by merely tightening the head and intake manifold bolts. If none of the head bolts were loose, you might want to pull the heads anyway and check to see if the head and/or intake manifold gaskets are damaged. My 2 cents worth.