2003 Trubute V6 with off white colored coolant. Here is what I know and can say:
Runs perfectly
Shifts perfectly
Been using Zerex G05 for years, no issues until now
No vapor or smell out of exhaust
No bubbles in overflow/degass coolant containter
No water or milkshake in oil. Oil level holds constant
No water or milkshake on Tran dipstick, level holds constant
Pulled trans cooler lines from the radiator, flushed out coolant and filled with water, milky came back almost instantly
No leaks out of radiator trans cooler fittings (no hoses connected, joineed the two trans cooler hoses together)
Have not done anything with the oil cooler at the filter yet.
Have not done compression check yet
Sample of milky coolant put in a clear glass bottle and after several days observed no change, no layering, no settling, no clearing, looks exactly the same as when I pulled the sample.
Tonight I added one bottle of K-Seal radiator stop leak. Ran it till thoroughly warm and circulated. Tomorrow will drain and refil with water and observe.

OK, I think that spells out all I know. I'm looking for your suggestions and comments. Thanks for you input and help.
Tom

 

Before you do anything having to do with the coolant perform a coolant chemical test.
Once you know that it is negative then it's time to consider a complete replacement of the coolant and cooling system cleaning.
If you have a refractormeter you can also measure the exact coolant to water % with may be helpful in a analysis of the coolant.

Compression test will not serve to solve your mystery however a cylinder leak down test is a better choice for determining the engine health regarding cylinder pressure loss.

Using any cooling system sealer before first finding our problem will increase the problem solving .......often times masking the initial problem which results in it returning unexpectedly and many times worse.
Without a emission exhaust tail pipe analyzer the human nose cannot smell small amount of water vapor or other non combustible elements that may be in the exhaust. You would be better off to proper read the spark plugs.

 

Did you get the issue resolved.. I am also experiencing the same symptoms.. MILKY coolant in radiator and reservior but no coolant mix in engine oil or transmission,, I removed the intake, spark plugs and the valve covers to have a better view of the inside, but no signs of coolant mix with oil.. Hopefully I get an answer... Thank you

 

Read post #2

 

@Callisto , After I flushed the coolant system with water and put in the K-Seal, then flushed again and then added new coolant, the coolant did not turn milky, stayed clear coolant color. My next door neighbor drove me crazy until I sold it to him, he has been driving it trouble free for over a year with no issues. I'm guessing I had a very small head gasket leak or head crack that the K-Seal fixed?????? I don't know. My neighbor is as far from a maintenance nut as you can get. He does not see the benefit of changing the oil or tran fluid or rotating tires. I told him I would do it for him. No go. His method is to drive whatever he has until it quits for whatever reason, then buy something and do it again. So I see my poor car sitting in his driveway being driven all the time and neglected. I pains my soul, haha. Anyway, thanks for your diagnostic suggestions but it is out of my hands. Tom.... Max told me to chill.

 

Sounds like you solved the issue question.
While I no longer recommend or suggest its use because on most forums members are not performance oriented "nuts" (like me) MOROSO CERAMIC SEALER work similar to K-Seal. I have successfully used MOROSO for decades for the repair (temporary) of even crack engine blocks. Unfortunately, as I said use to suggest its use, but people just seem to be resistant to reading instructions for use of anything ............


I feel for you seeing your old car. I found years ago I don't give or sell to friend's family or close neighbors. You know they will not take of the car as well as you did, and evetime something goes wrong they sorta think you should fix it....FREE!