Water pump, thermostat and coolant (NC)
Owners say water pump failures are rare on the NC. This page lists who sells the pump and thermostat and what owners said about coolant. It is not a repair guide.
How to read it. Seller claims are as read on each seller's own page on 1 October 2026. Owner accounts are from Miata.net forum threads, dated below, and are individual experience, not advice. There are no prices on this page, and nothing here was bought or tested.
| Seller | What it says it offers | Fits (as stated) |
|---|---|---|
| Flyin' Miata, water pump for the NC (MZR engine) | a "quality replacement water pump" with a one-year warranty; it says the brand may vary and that it only uses products it would put in its own vehicles | 2006-2015, including the PRHT |
| Moss Miata, water pump | listed as "Water Pump"; the page gives no other description | 2006-2015 |
| Moss Miata, thermostat, long housing, aftermarket | listed with no further description | 2006-2015 |
| Mazda-Parts.com, Mazda water pump LF94-15-100A | the genuine pump, with its gasket (LF01-15-116A) included; the listing is shared with other 2.0 litre non-Skyactiv Mazdas, and notes a refundable manufacturer core charge | shown for a 2008 MX-5; NC |
| Jim Ellis Mazda Parts, Mazda thermostat kit LF70-15-170 | a kit with the thermostat, housing and gasket; it fits several 2.0 litre non-Skyactiv Mazdas, with Miata notes "from 9/1/06" and "to 3/8/06", so check which applies to your build date | Miata/MX-5, 2.0 litre |
Moss's search results also show a thermostat gasket for the NC (916-617) and a Mazda coolant overflow hose; I did not open those pages. For the plastic expansion tank, see the cooling page.
Coolant
TascaParts lists genuine Mazda FL22 coolant, part 0000-77-508F-20, as a special order from Mazda, with the fit checked against your VIN at checkout. Mazda-Parts.com lists the same number but says the product contains hazardous materials it cannot ship, with local pickup only in Torrance, California. Neither page says the container size or whether it is premixed, so check that before ordering.
What owners said
- Do I need to replace the pump? (January 2013). A buyer looking at a 58,000-mile 2006 asked about a pump interval. One reply said he knew of no NC pump failures, with many cars past 100,000 miles on the original, and credited the factory coolant: he said the pump's life depends on the coolant being silicate-free, and that the factory FL22 is a silicate-free HOAT formula with a phosphate additive. He named two alternatives to genuine FL22, Zerex 675130, which he uses, and Ford Motorcraft VC-10-A2, and warned that an incompatible coolant mixed with FL22 can turn into a black gel that clogs the system, and that a "compatible" coolant that is not silicate-free HOAT with phosphate could wear out the pump bearing. He said the factory fill lasts ten years or 100,000 miles. Another poster told the buyer not to worry about the pump at that mileage, and that spark plugs and fluids were the main items. (Miata.net thread.)
- A thermostat code (October 2018). An owner of a 2008 with 115,000 miles got a P0126 code and suspected the thermostat, and had read that Mazda recommends a pump at 10 years or 120,000 miles. One reply said the only cooling system item in the maintenance schedule is changing the coolant at 10 years or 110,000 miles, and that he replaced his pump during a flush but did not need to. Another pointed out that P0126 means the coolant is not warming up enough, the opposite of what a failing pump would cause, and said he still had his original pump. (Miata.net thread.)
Not covered yet
- A premixed FL22 coolant with its size stated, and the exact Mazda thermostat part for each NC build date.
- The ND's cooling parts beyond the reservoir.
© 2026 Fischer Interactive LLC. Written for the Ref Sensor app's Miata users. The seller's page is the authority.