Milky coolant

Check transmission fluid known issue of transmission cooler tank leaking into radiator.
Search for SMOD.

05 is known for bad Denso radiators. That in time allowed coolant to mix with ATF. Hopefully coolant hasn’t found it’s way into the transmission.
But yes, a blown head gasket can mix engine oil with coolant.
Check oil and transmission for contamination.

Nail Grease said:

05 is known for bad Denso radiators. That in time allowed coolant to mix with ATF. Hopefully coolant hasn’t found it’s way into the transmission.
But yes, a blown head gasket can mix engine oil with coolant.
Check oil and transmission for contamination.

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Had my oil changed on Thursday last week. This happened Friday. Today the oil on the dipstick showed no signs of contamination. I'll check the transmission fluid in the morning.

spoconnell23 said:

Had my oil changed on Thursday last week. This happened Friday. Today the oil on the dipstick showed no signs of contamination. I'll check the transmission fluid in the morning.

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There is a chance that the atf or oil contaminants the coolant while not contaminating the engine or transmission fluid. Hopefully that’s the case. My advice would be to not run the vehicle.

Nail Grease said:

There is a chance that the atf or oil contaminants the coolant while not contaminating the engine or transmission fluid. Hopefully that’s the case. My advice would be to not run the vehicle.

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Haven't ran it since it happened. Just trying to figure out where to go from here.

spoconnell23 said:

The trans dipstick isn't showing much of any fluid on it, which raises other concerns. Here are pictures of the oil dipstick and the fluid in the overflow tank. View attachment 168668 View attachment 168669

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Your engine oil looks clean. Can you get a sample of atf? Clean ATF is pink/red, but old used ATF can be brown. The fact the ATF is low is a concern.

spoconnell23 said:

This is all I could get off the ATF dipstick.

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I’d open the drain plug to see the ATF condition. Reach in under the front bumper, an pop in a 3/8 ratchet (No socket), and pull to break loose.

spoconnell23 said:

This is all I could get off the ATF dipstick.

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I’m not seeing any hint of red on that rag. That, the tranny fluid level being low, and the tan mixture in the coolant overflow reservoir aren’t looking too hopeful. What color is the coolant in the radiator?

road2cycle said:

I’m not seeing any hint of red on that rag. That, the tenant fluid level being low, and the tan mixture in the coolant overflow reservoir aren’t looking too hopeful. What color is the coolant in the radiator?

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I’m holding out with a little hope that if it is ATF mixing in the coolant, that it pumped out of the transmission and not back in.

Looks like whatever is in the overflow reservoir is also in the radiator. That makes sense. I’d still want to know what that substance is and find out why the tranny fluid level was so low.

Other observation is there is non-OEM coolant in the system. Honda coolant is blue.

ATF in the coolant can be overcome. Just don’t want coolant in the transmission. It can do serious damaged. As stated, since ATF is unmeasurable on the dipstick, hopefully it pumped out into the radiator break, but didn’t draw back in. The ATF needs multiple drain and fills as soon as possible. That would require the radiator, radiator hoses, ATF lines to the radiator be replaced. A flush of the coolant system need to be performed. Something that won’t harm the system but would remove the residual ATF (Do not use tap water).

If your vehicle were mine, I’d disconnect the ATF lines to the radiator, create a loop bypassing the radiator. Drain out old ATF and fill with Valvoline MaxLife ATF. This would allow me to drain the block and old radiator and use distilled water and a coolant flush product (someone suggested dawn dishwashing liquid to clean out ATF). Continue to do multiple flushes until clear. Replace radiator and hoses. Then add the appropriate coolant compatible for Hondas. 50/50 mix. Reattach ATF lines after multiple drain and fills of the ATF.