Transmission fluid in coolant.

Hey guys I have a 2013 Toyota tundra 4.6

my radiator cracked. While changing it I noticed the coolant looked like attached photos (with new coolant next to it) can anyone tell me if they have experienced an issue with there trans oil coolers or if you recognize this coolants color and consistency?

 

There is a fluid warmer at the transmission, which uses engine coolant. It is attached to the transmission fluid thermostat, if your truck has an ATF cooler. If you do not have an ATF cooler, the warmer is still present on the outside of the transmission.

It's possible that the warmer has had an internal failure causing the mix. You definitely want to see what your transmission fluid looks like. Drain it out now from the pan to check. Do not run the truck if coolant is mixing with the ATF. The tainted ATF can cause transmission failure.

There is no transmission fluid cooler within the radiator though.

I would think if motor oil was mixing with the coolant (via head gasket) that it would be darker and brown in appearance.

 

Ditto.