Hi There,
I just did a radiator flush and found the coolant coming out was grayish color. That was weird... So i flushed it out with some water a few times and poured new coolant into the cbr600rr... The new fluid is gray again.

What does gray coolant represent (it was pink originally)?

Originally I thought ... busted head gasket? but here are some facts...
I'm losing no coolant from the reserve tank. Visually checked around water pump and cannot see any leakage. Bike running at normal temp. normally runs on 178 over freeways, yesterday with 90 degree + weather, was running hot in the 200's while city riding. I am figuring it was normal. Fan kicks in at 219-220 and reduces the temp to 212.

Took it to a local shop and they suggested for me to re-flush with Honda specified coolant (that's supposed to be blue?) and see if it changes color again.

By the way, I checked the old coolant it changed color back to green (from gray when i originally took it out)

What can be a cause for a grayish coolant?

 

the wrong type of coolant having a chemichal in it that is reacting badly with one of the alloy metals somewhere in the cooling system of the engine
If its not foamy with oil sitting on top from a gasket leaking oil in id call it a chemical reaction. ive heard stories of it but never actually seen it.

this thread is a few old, what did you figure out? anything?