[merlin09]

I have noticed while doing my last oil change that coolant is leaking and running down onto the oil pan and becoming hard and blue crust.
cannot locate where it is coming from. Car has 265K miles with all original hoses and thermostat. Guess i could change all that first???

thanks

 

[Carsmak]

I'd start with the radiator, could be a pin hole leak. Check your coolant levels and either add Honda Type 2 or distilled water. No tap water.

 

[IanRTL]

Start by tracing where it ISN'T. If you follow from the oil pan up and see if there is any blue residue anywhere else, that will at least narrow down where you need to look. Has the radiator ever been replaced? If not, it's a good idea to do so as preventative maintenance.

 

[ridged]

A pressure test will generally make it pretty easy to track down leaks. One can purchase relatively inexpensive DIY testers or take it to a repair shop.

 

[oarnold]

Blue could also be windshield cleaner?

If you have a 2006, that mileage and original equipment, read up on transmission cooler/radiator interface and the strawberry milkshake of death.