# Thermostat initial opening temperature (NB2 2004–2005, non-turbo)

Canonical URL: https://miatatorque.com/spec/thermostat-initial-opening-temperature-nb2-2004-2005/

Applicability: NB 2004–2005 (BP-Z3) — Actual 2004 and 2005 factory evidence; initial-opening range follows the 2003 procedure.

Confidence: fsm

86.5–89.5°C {188–193°F}

Always confirm against your factory manual. Match every restriction and follow all stages and procedure notes. Disputed claims must not be automatically resolved. The complete record below preserves every printed unit, source claim and procedure.

```json
{
  "id": "thermostat-initial-opening-temperature-nb2-2004-2005",
  "name": "Thermostat initial opening temperature (NB2 2004–2005, non-turbo)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NB",
      "years": [
        2004,
        2005
      ],
      "engines": [
        "BP-Z3"
      ],
      "note": "Actual 2004 and 2005 factory evidence; initial-opening range follows the 2003 procedure."
    }
  ],
  "kind": "non-torque",
  "value_text": "86.5–89.5°C {188–193°F}",
  "procedure": {
    "notes": "Place thermostat and thermometer in water, heat and check the valve. Use 86.5–89.5°C initial opening for the single-valve NB2 thermostat, including Mazdaspeed. The 2003 procedure supports this range; 2004–2005 procedures/tables print 83.5–86.5°C, retained verbatim in citations where present. Full-open temperature is 100°C; minimum full-open lift is 8.5 mm. Do not apply the NA main/sub valve distinction to these NB records."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-2004",
      "page": "Thermostat Inspection (PDF pp. 687–688); Engine Technical Data (PDF pp. 929–930)",
      "as_printed": "Initial-opening temperature\n°C {°F}\n83.5—86.5 {183—187}",
      "verified_years": [
        2004,
        2004
      ],
      "document": {
        "id": "fsm-2004",
        "tier": 1,
        "title": "2004 Mazda MX-5 Miata Workshop Manual (electronic manual capture)",
        "covers": [
          {
            "gen": "NB",
            "years": [
              2004,
              2004
            ],
            "engines": [
              "BP-Z3"
            ]
          }
        ],
        "note": "Normally aspirated BP procedures audited; turbo procedures are covered separately."
      }
    },
    {
      "source": "fsm-2005",
      "page": "Thermostat Inspection (PDF pp. 749–750); Engine Technical Data (PDF p. 1047)",
      "as_printed": "Initial-opening temperature\n°C {°F}\n83.5—86.5 {183—187}",
      "verified_years": [
        2005,
        2005
      ],
      "document": {
        "id": "fsm-2005",
        "tier": 1,
        "title": "2005 Mazda MX-5 Miata Workshop Manual (electronic manual capture)",
        "covers": [
          {
            "gen": "NB",
            "years": [
              2005,
              2005
            ],
            "engines": [
              "BP-Z3"
            ]
          },
          {
            "gen": "NB",
            "years": [
              2005,
              2005
            ],
            "engines": [
              "BP-Z3-TURBO"
            ],
            "trans": [
              "6MT"
            ]
          }
        ]
      }
    },
    {
      "source": "fsm-2003",
      "page": "Thermostat Inspection (PDF p. 655)",
      "as_printed": "Initial-opening temperature\n°C {°F}\n86.5—89.5 {188—193}",
      "document": {
        "id": "fsm-2003",
        "tier": 1,
        "title": "2003 Mazda MX-5 Miata Workshop Manual (electronic manual capture)",
        "covers": [
          {
            "gen": "NB",
            "years": [
              2003,
              2003
            ],
            "engines": [
              "BP-Z3"
            ]
          }
        ],
        "note": "Normally aspirated BP procedures audited; turbo procedures are covered separately."
      }
    }
  ],
  "jobs": [],
  "system": "cooling",
  "component": "inventory-pass-2026-10",
  "componentName": "Service measurements and fasteners",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/thermostat-initial-opening-temperature-nb2-2004-2005/"
}
```