I think I've got major problems with my 07 RDX with about 150k miles. I did the first of the 3x3 transmission drain and fill and there were metal shavings/filings on the drain plug (but no "chunks" FWIW). The fluid was dark red as opposed to bright red and it was last changed about 25k miles ago. Then I checked the coolant overflow tank and there's a lot of milky white fluid mixed with a bit of blue coolant (see pic). What has me confused is if the ATF fluid was mixing with the coolant, I would expect to see "strawberry milkshake" with the coolant...now I'm wondering if the coolant is mixing with engine oil and I'm looking at a blown head gasket or similar, on top of whatever's going on with the transmission.

Is there a way to check the rad to see if coolant is mixing with ATF fluid? I think there's a transmission radiator attached to the main rad, and there's a risk the two fluids get mixed together.

Is there an easy way to confirm if combustion gases are in the coolant?

Pix of the coolant are below: https://imgur.com/a/2007-acura-coola...s-mean-BxmG5pL

Thanks.

 

If youre seeing ATF in the coolant/radiator, it means the internal cooler of the radiator that sepRates the coolant and ATF have failed and you need a new radiator asap, coolant in the trans is no good.


get a Denso radiator here:
https://www.rockauto.com/en/catalog/...,radiator,2172


2 gallons of Honda Type 2 coolant, and 3+ quarts of ATF DW 1 and you’ll be good as new

 

For sure. I'm wondering if there's some way to confirm 100% that the ATF has coolant in it. I'm not sure what to make of the white fluid in the rad's overflow tank -- could ATF cause that? Could I physically inspect the rad and/or the trans cooler to see if there's a breach somewhere?