Life after an oil cooler failure……

[Stalkerfiveo]

So, it happened. My 97 Cobra’s o-rings in the oil cooler finally gave up after 27 years. With that, your typical mixing of oil and coolant and a lovely brown smoothie in my oil pan and radiator.

Today I drained the oil and radiator. Removed the oil filter and luckily my local Ace had a 1/2” Allen socket so I could remove the huge bolt through the cooler.

I rigged up a PVC to garden hose adapter so I could pressure flush the radiator and the block. Hooked up to the upper radiator hose on one end and blew out the radiator til it was clear. Then the other end of the upper hose and blew out the heads and block through the crossover pipes as best I could til clear.

That’s where I’m at now. My o-ring kit is supposed to arrive from LMR Monday so I can put it all back together and add fluids back in.

That said, how should I proceed from a fluids standpoint? There’s remnants of oil in the coolant passages, and remnants of coolant in the oil pan.

I’m in GA, no risk of freezing for a while. Should I even bother with antifreeze? Or just fill it with distilled water to save money? How many times should I expect to have to drain and refill til it’s clean?

As for the oil pan, should I even drive it? I was think about buying the cheapest two 5qt jugs of oil I can find and cheapest 2 oil filters I can find. Just so I can crank it and let it idle and heat cycle, then immediately do an oil change. Do that twice, then the 3rd time put in a good synthetic and Motocraft filter.

Thoughts? Experiences? I’m open to any advice to save money AND my motor.

 

[I_like_turtlez]

Absolutely nightmare inducing.. not something I wanted to think about on Saturday night *chugs beer*

But about your questions..



"Should I run straight distilled water"

-Never do this, the water will boil off as you're driving it, coolant doesn't just prevent freezing, it also raises the boiling point of the mixture and prevents corrosion

"What to do about my forbidden oil pan milkshake"

-I'll tell you what I would do without pulling the oil pan off; buy 18 quarts of the cheapest synthetic(Quakerstate), 3 bottle of Seafoam(one for each oil change) and let it run for about 20 minutes in-between each change out. Might even toss a quart of straight diesel in that sucker, engine will come out practically new LOL

 

[Stalkerfiveo]

Absolutely nightmare inducing.. not something I wanted to think about on Saturday night *chugs beer*

But about your questions..



"Should I run straight distilled water"

-Never do this, the water will boil off as you're driving it, coolant doesn't just prevent freezing, it also raises the boiling point of the mixture and prevents corrosion

"What to do about my forbidden oil pan milkshake"

-I'll tell you what I would do without pulling the oil pan off; buy 18 quarts of the cheapest synthetic(Quakerstate), 3 bottle of Seafoam(one for each oil change) and let it run for about 20 minutes in-between each change out. Might even toss a quart of straight diesel in that sucker, engine will come out practically new LOL

I like the Seafoam idea!

 

[01yellercobra]

I was going to suggest some kind of oil flush as well. Seafoam is good stuff.

For the cooling system I'd get some flush for that as well. You can run everything together through a couple heat cycles.

 

[venom1997]

So does the oil cooler core fail or the oring? I’ve never heard of one failing as far as the cooling system goes straight water just till it gets to operating temp then drain and repeat till it’s clear use a flush with it revive the thermostat housing and flush it out with garden hose a few times


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[Stalkerfiveo]

So does the oil cooler core fail or the oring? I’ve never heard of one failing as far as the cooling system goes straight water just till it gets to operating temp then drain and repeat till it’s clear use a flush with it revive the thermostat housing and flush it out with garden hose a few times


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The o-rings fail and the oil and coolant mix.

Sadly, I think this has smoked my motor.

 

[I_like_turtlez]

The o-rings fail and the oil and coolant mix.

Sadly, I think this has smoked my motor.

I like the Seafoam idea!

Seafoam is a great product that's easy to use, I've seen it clear out fuel systems, free up stuck valves and rings etc

I pour a can in my gas tank every month and add it to the crank case a few hundred miles before every oil change on my vehicles; can confirm it keeps gasoline fresh for at least 18 months

Can be used as a home solution to clear out the intake manifold and intake valves as well when aerosolized




I don't think your engine is a goner but I'd get it flushed out as soon as possible, it will take several flushes for the oil to finally drain out clean

 

[Stalkerfiveo]

I don't think your engine is a goner but I'd get it flushed out as soon as possible, it will take several flushes for the oil to finally drain out clean

Pretty sure it’s seized. Replaced the starter and it still won’t turn over. Removed the serpentine belt and pulled all the plugs. Still can’t turn the crank with a breaker bar and 18mm socket at the harmonic damper.

I’m going to have it towed in to a local Mustang shop and let them inspect it. I’m afraid the issue went on longer than I realized and the coolant/water ruined the main bearings. I’ll let them decide the true extent of the damage, then decide if we’re rebuilding or replacing.

 

[venom1997]

Yeah I don’t think it would actually hurt the motor man I’ve always flinched out motors with 15w40 diesel oil(detergents are high) and 1 qt of diesel fuel run in till it gets warm and drain do it one more time and repeat 3rd time do 15w40 diesel oil and 1 qt marvel mystery oil on a new filter drive around 30-50 miles drain and then do your normal oil change5w30 synthetic and new filter


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[venom1997]

Oh shoot so it still won’t turn over? Remove the plugs and try starting it


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[venom1997]

Seafoam is a great product that's easy to use, I've seen it clear out fuel systems, free up stuck valves and rings etc

I pour a can in my gas tank every month and add it to the crank case a few hundred miles before every oil change on my vehicles; can confirm it keeps gasoline fresh for at least 18 months

Can be used as a home solution to clear out the intake manifold and intake valves as well when aerosolized




I don't think your engine is a goner but I'd get it flushed out as soon as possible, it will take several flushes for the oil to finally drain out clean

Yes Seafoam or marvel mystery works amazing


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[I_like_turtlez]

Pretty sure it’s seized. Replaced the starter and it still won’t turn over. Removed the serpentine belt and pulled all the plugs. Still can’t turn the crank with a breaker bar and 18mm socket at the harmonic damper.

I’m going to have it towed in to a local Mustang shop and let them inspect it. I’m afraid the issue went on longer than I realized and the coolant/water ruined the main bearings. I’ll let them decide the true extent of the damage, then decide if we’re rebuilding or replacing.

Sounds like it somehow hydro-locked; even with a bad bearing you would be able to move it at least some in one direction or the other


I told you how to test the starter in your other thread, you replaced a good starter lol Oof

 

[Stalkerfiveo]

Oh shoot so it still won’t turn over? Remove the plugs and try starting it


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Removed the plugs and the starter still won’t turn it. Can’t spin it with a breaker bar on the harmonic balancer either.

Sounds like it somehow hydro-locked; even with a bad bearing you would be able to move it at least some in one direction or the other


I told you how to test the starter in your other thread, you replaced a good starter lol Oof

No, Oreilleys bench tested the old one. It was actually bad. Seized.

 

[Cobra Jet]

Those Ford oil coolers are THE worst design and really do not have any real benefits. That design Ford has used since the SVO’s debuted, same design then carried into the Mustang SSP’s, then later again carried into the 94/95 Cobras… and again carried forward with similar design elements for the later Cobras…

It’s a junk design because of the very fact once that O-ring deteriorates it’s a time bomb waiting to destroy the engine…. Replacement O-rings are available, but if the damn thing failed once, would you REALLY want to put the same poor design back onto a rebuilt or new engine?

I’ve always removed the 86-95 Ford 5.0 oil coolers and then used the proper engine block adapter so a full size oil filter could be used on the engine. My 94 Cobra cooler is stored away, hasn’t been on the car in the 21 years I’ve owned it…and there isn’t any detrimental effects from removing it. It was the first “mod” I did knowing it’s a poor design waiting to eventually fail.

You might be able to do the same on the 96+ Cobras (eliminating the factory cooler and lines).

If you want an oil cooler that works, you need a aftermarket one that is air cooled and has no way of mixing oil/coolant when it goes south.