Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

By the end of yesterday, I was hoping to finish replacing all coolant hoses but with so many corroded pipes, flange at the thermostat and dirty TH body and intake manifold, had to leave the last two hoses at the oil cooler for tomorrow and then fire up the engine.




On this NSX, the coolant was seeping from several places but I think it was also seeping from the thermostat cover area as well. The build up of blueish debris is the proof that the coolant was in contact with the outside air under heat.

Lots of corrosion but nothing new and possibly the same on your NSX if the coolant was not replaced within the last 4 - 5 years.
Didn't want to polish the pipes too thin so stopped at this level. Silicone compound should do good job in preventing further corrosion.







Addition to the thermostat cover, the housing itself showed lots of corrosion.
Had to use ceramic scraper to carefully re-condition the surface to this level.
New spec thermostat installed.








New coolant hoses followed by the new tank and cap.