Oil and coolant mixing

[DumpTruck]

I searched through the forums and it seems there are 2 opinions.
1 . The oil cooler will only put oil into the coolant because oil pressure is higher than than coolant.
2. The oil cooler will cause both issues .
Here is my thought
When the engine is running oil goes into the coolant.
When engine is stopped oil pressure goes to zero then the coolant pressure forces coolant into the oil.
Opinions,facts ....what does anyone think?
I have fresh un mixed in coolant in my oil filter. Oil in pan is obviously contaminated but no coolant at the bottom of oil pan.
Thanks
Tim

 

[Old Goat]

I went through that exact same thing several years ago. About 5 yrs ago.
Checked oil one morning, take a trip over the mountains to Ca. for a Funeral.
Next morning back home checking oil and notice all black in Coolant Bottle, and oil in Radiator.

3 guys came back saying Oil Cooler.
Found a remanufactured MotorCraft off Parts Geek.

This is January, and in between Snow Storms on the patio R&R the dang thing. There is 4 "O" Rings, 2 on ea end. They were old and cracked. So the Cooler was probably ok, just the Rings were bad. There is also 2 paper gaskets also, comes as a kit.
Doing a search for a new cooler, they are mostly from China no matter who sells them.

Might be a dealer some where that has one on a shelf. Pricy, probably close to $500.


Goat

Fun part now is flushing out the cooling system.

 

[IDIBRONCO]

When the engine is running oil goes into the coolant.
When engine is stopped oil pressure goes to zero then the coolant pressure forces coolant into the oil.
Opinions,facts ....what does anyone think?

This certainly seems likely in your case. Is there any oil in your cooling system? You didn't mention that.

 

[Clb]

Fwiw
Goat
ftw

Just know you gotta put the cooler thru he ll (take that auto censor) in order to make the hard parts leak.
Buy a seal kit.
O rings seal against pressure, either direction it doesn't matter.
The paper is on the block and has 2 bolts clamping to the block.
Unless you have mechanical damage or loose mounting it's allways seals.
Now the secret sauce to clean the cooling system is another thing....

 

[Minuteman96]

Classic Diesel Designs sells an oil cooler reseal kit. If it ends up being the cooler, I’d recommend resealing before buying a new one. Probably less expensive and the modern quality is no match for back in the day.

 

[ihc1470]

Dawn soap cleans up the cooling system. May take a couple of times.

 

[Booyah45828]

Use cascade. Dawn creates bubbles, which is something you don't want in a diesel or other cavitation prone engine.

 

[frankenwrench]

Use cascade. Dawn creates bubbles, which is something you don't want in a diesel or other cavitation prone engine.

I used simple green to clean my coolant system out. But then let my worry get the best of me and replaced every gasket, hose and seal right after thinking it may have damaged them in some way

 

[Old Goat]

I did 6 flushes with cascade or? to finally get to where there was no trace of oil in the discharge.
Drained the Radiator as well as the two Block plugs, one on each side.
Then 6 flushes with Distilled water to make sure all the soap was totally flushed out.
Over kill? Maybe, but that is what I did.

Used one of these pans from HD

Medium Mixing Tub A-41 - The Home Depot

This Medium 10 Gal. 28 in. D x 20 in. W x 6 in. H mixing tub is made of heavy-duty resin yet flexible. With a variety of options this multi-purpose tub offers endless uses. Great for Aquatics, Concrete,

www.homedepot.com

Then filled it with Fleet Charge or ? 50/50 mix with Distilled water.

Replaced all rubber hoses as well as the Block Heater. Noticed it was green around the "O" Ring area al looked like it started to seep fluid.
Had a new one so stuck it in.
OH and replaced the Thermostat.

I kept the old cooler, one of these days will clean it up, Some of the tubes were plugged.
Probably ok, but as long as I was digging into it, I just didn`t want any problems later on.

Now I are an expert going through the learning curve, Next one will be quicker.


Goat

 

[Booyah45828]

I used simple green to clean my coolant system out. But then let my worry get the best of me and replaced every gasket, hose and seal right after thinking it may have damaged them in some way

Probably fine. I like super clean myself. Dawn is probably fine too. They'll all likely work to remove the oil.

I'm just repeating what I was told by an older tech about the bubbles and cavitation and it made sense to me. In the shop I use cascade, probably too much at a time to be honest, and there is rarely ever bubbles in what's being drained, more like a foam. Anyways, when I would use superclean to remove dexcool sludge/mud, it definitely made a lot more.

 

[DumpTruck]

Thanks to all for the advice . I will be pulling the oil cooler as soon as I can . I sincerely hope it is the oil cooler . I definitely had antifreeze in the oil . After running the engine then letting cool overnight there was fresh un mixed antifreeze in the oil filter . Seems likely this migrated in there while the engine was cooling . Wish me luck thanks again
Tim

 

[Clb]

Look up the tech 101
Bust loose the driverside eng. Mount and jack it up so you can clear the exhaust manifold