Oil in coolant?

[Cardriver333]

Today is the first time I've seen this and I looked at my coolant within the past couple of days. I replaced my spark plugs, idler pulley, Serpentine belt, belt tensioner, and went for a drive. Changed oil and filter after and at the end of all of it noticed some dots of what looked like oil. What should I do?

 

[Dino Dino Bambino]

That looks more like automatic transmission fluid. If your car has an auto tranny, the radiator will have an integral ATF cooler and it's possible there's an internal pinhole sized leak into the coolant core.

 

[Cardriver333]

Thanks for the reply! I did replace some atf the week before. Actually I replaced almost all of the fluids recently, at that time I did top off the coolant so maybe I just cross contaminated then and hopefully there is no hole.

 

[Pentalab]

Dunno abt the V6, but on my 2010 GT auto, the tranny cooler is totally separate, and sits between the eng rad and the AC rad. And both the V6 and the GT use the same 5r55s auto tranny.

 

[Cardriver333]

Yeah, it is a separate unit on mine also. I'm thinking I probably just got a little Trans or motor oil in the expansion tank when I topped it off