Oil Pan Full of Coolant

[Zephyr]

Well, I lurk here and learn lots but usually don't need to post questions as someone has already received the answer...but I'm not finding the answer easily.

I just put my 7.3 back in following a long drawn out reseal, clean, rebuilt heads, oil cooler, turbo, injection pump, new injectors, lift pump, water pump, etc. I filled the radiator with water and coolant flush (no antifreeze), to perform a better coolant system flush on startup and then refill later with antifreeze. I was performing intermittent engine cranking last night to get fuel flow started out of the tanks. After deciding to siphon some fuel through the lines, I quit for the evening.

This am the garage floor is covered with 1-2 gallons of oily coolant, a slow drip is coming from the bell housing bottom plate, the radiator appears empty (or low) and the dipstick is very high with oil/water (coolant). Obviously I have an oil pan full of foreign liquid that needs draining ASAP. There are no other visible engine leaks around water pump and oil cooler.

My questions are:

Any easy way to identify whether the coolant is coming from the oil cooler or water pump? Since it didn't ever fire and the huge quantity of coolant in the pan a head gasket leak would be unlikely. The engine has previously been sleeved on all 8 as well.

What else should I do to prevent internal rusting, damage while trying to identify the cause?

What other sources of coolant should I consider that would dump gallons into the oil pan while sitting overnight?

Thanks for any advise.

 

[Thewespaul]

I’d put money on the sleeves aren’t installed right or just not sealing. You can pull the cooler off and make some block off flanges to remove that from the possible causes.

 

[riphip]

Sounds to me like: a crack in the block at a cylinder (read they were sleeved) or leak behind water pump. You did state it will turn over so not hydrolocked

 

[Zephyr]

Update, drained 5+ gallons of water from oil pan plus the remaining engine oil. That is a huge amount for an overnight leaky gasket! Drained the radiator, maybe 2 gallons of water. I am guessing the radiator water level was about even with the upper extent of the lower radiator hose . Am I thinking right that the remaining coolant would be leaking out from a lower portion of the engine (i.e. oil cooler) versus higher up like a head coolant port since the radiator was quite empty? I am putting my money on my first, errant rebuild of the oil cooler. Engine was sleeved 40,000+/- ago. I had no coolant problems before the teardown, so I doubt that is the problem. I just had horrendous oil pan, valve cover, and moderate rear main leaks that caused me to pull the engine. The shop that did the previous rebuild was highly recommended on here years ago (now out of business?) but #7 valve guides were horrible and required a new head and remachining. No hydrolock last night, cylinders all looked great, no rust, at teardown time but I didn't try cranking today before draining the engine of all the coolant.

Anything I should be doing immediately with the engine, because the bottom end was filled with coolant before I pull off the oil cooler? What is the best way to test the cooler for leakage from coolant to oil side?

 

[Thewespaul]

Pull the cooler off and take it apart, if it was leaking it is usually pretty obvious where. Water pump is good suggestion as well, if the sleeves weren’t leaking before they should be fine

 

[Zephyr]

Thanks. You talked about block off flanges. Am I correct in understanding that would be to block off all oil cooler passages to pressure test the coolant system? I couldn't start it that way, correct?

I am planning to remove the serpentine belt, fill the oil pan with new oil and a new filter and crank it a little to get non-water filled oil into the bearing surfaces tomorrow. Any suggestions beyond that while I pull the oil cooler?

 

[Thewespaul]

I was just referring to replacing the oil cooler with flanges to bolt in its place so you can remove that as a potential issue. You could just flush it out with some clean diesel to save on the oil.

 

[IDIBRONCO]

If you can't get the oil cooler end caps to go all the way on, you need to pull them completely back off instead of just part way. The o-rings tend to get hung up and seem to almost always (for me) pull away from their seating flange. This could cause an it to not completely seal between the oil and coolant passages. I'd bet this is what happened.

 

[Zephyr]

Thanks everyone for your help. I pulled off the cooler today and found a pretty large nick in the smaller o-ring on one end. I had followed previous manuals doing the rebuild and put that o-ring in the header instead of on the bundle. I have seen in other recommendations to put both on the bundle before assembly. Is this the general consensus? I can see how it would be much more prone to damage with the original method. Waiting on new o-rings and gasket and hope to reassemble tomorrow. I rented a coolant pressure tester from O'Reilly for a quick check and to make sure the water pump isn't a contributor so I hopefully don't have to do this again!!

Anyone have a use for 11 gallons of oil/water mix?

 

[genscripter]

While you are waiting for those o-rings for your oil cooler, use my DIY tester to see if your oil cooler will hold pressure: http://www.nickpisca.com/diesel/engine/diy-7-3-idi-or-powerstroke-oil-cooler-pressure-tester/

Considering your coolant-in-block leak was rather extensive, the hole allowing the transfer would be substantial, and likely identifiable with my method.

Also, when you are doing the o-ring job, don't force it:

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[Zephyr]

I placed a thick sheet gasket between the block and oil cooler manifolds, pressure test normal-no other leaks! Rebuilt oil cooler, pressure test again-no leaks, maintained pressure for hours.

Today, she roared back to life after a 10 month project. Thanks everyone for your assistance.

 

[riphip]

Glad you found your problem & was low price fix

 

[IDIBRONCO]

Same here.