DESCRIPTION
Forever fix the risk of your NC motor overheating because of a stock expansion tank failure. The NC is the ONLY generation of Miata where the overflow is a pressurized critical part of the cooling system and when the original plastic version fails you can have the motor quickly destroyed with overheating, often before the driver has a chance to notice the temp gauge spiking upwards. This all metal tank prevents that potentially very expensive failure.
Virtually identical to the super popular Moroso tank that we developed and have sold fold years, Koyo decided to get in the game so we now also have this tank for those who are fans of the Koyo brand. We would say that the Koyo has the nicest finish of all!
Direct replacement for your factory plastic coolant expansion tank. All aluminum and TIG welded with a machined aluminum neck that takes a factory cap. All of the inlets and outlets are positioned to match up with the factory hoses. The tank mounts to the same location as the factory tank and is built with the same dimensions for an easy fit. Includes view window on the side to check coolant level.
Stock plastic tanks are ticking time bombs because as they age they crack and when they crack the coolant pressure is lost and the motor overheats. Unlike the earlier Miata where an overflow leak was not big deal, the NC relies on this tank to be a pressurized part of the cooling system, as soon as a crack forms pressure loss causes the engine to overheat and the motor is usually destroyed. We have NC Generation Miata arriving on flatbed tow trucks every week with blown motors because the owner didn't change the plastic tank until too late. So we decided it was time for a "lifetime" solution. This tank is the solution. It will not fail over time like the factory tank, and looks great as well!
Installation NOTES:
CLAMPS: While the factory squeeze-clamps on the hoses can be re-used, they get weaker the more they are removed/installed and having a tight seal on all the hoses is important since this tank is pressurized. We recommend changing the squeeze clamps out for worm drive hose clamps which can be found at any auto parts store. #4 worm clamp (x2) for the top two nipples, #10 worm clamp (x1) for the bottom.
CAP: You might need to very slightly adjust the 'tangs' on the factory radiator cap to fit the new metal neck with same tension as it did on the factory softer plastic neck, takes a few seconds to do with pair of needle nose pliers.