Thermostat Housing 8-94172420-0 8941724200 For ISUZU TFR TFS Campo Pickup 4JA1 4JB1 4ZE1 — OEM-Grade Aluminum Housing Cap, With Gasket, Metal Construction

Thermostat Housing Cap with OEM references 8-94172420-0 / 8941724200 is a verified replacement cooling-system component for ISUZU TFR / TFS / Campo pickups. Manufactured from aluminum die-cast, this housing seats and seals the engine thermostat, forming the upper half of the thermostat cavity and providing the coolant outlet connection to the radiator hose. It is a direct OEM replacement with ISO9001 certification, supplied with a gasket (Dorman aftermarket reference 902-5064, cross-referencing ISUZU OE 8941724201).

• Material Verified: Aluminum die-cast — confirmed by Japanese and Polish supplier listings describing the part as an aluminum thermostat housing cap / cover.
• Construction & Included Components Verified: Dorman 902-5064 (direct cross-reference to 8941724201) specifies Material: Metal, Gasket or Seal Included: Yes, Housing Neck Angle: 45°, Outside Diameter: 1.25 in, Mounting Hole Quantity: 2.
• OEM Cross-Reference Verified: 8-94172420-0 / 8941724200 is the primary reference; 8941724201 is confirmed as a direct OE cross-reference via Dorman; 8-94172-420-1 appears in ISUZU TFR/TFS catalogs as the water outlet pipe version of this housing family.
• Vehicle & Engine Coverage Verified: Confirmed for ISUZU TFR/TFS-LHD (1993–1996, 1999–2003), TFR/TFS-RHD (1999–2003), Campo, and Opel Campo applications, with engine coverage including 4JA1, 4JB1, 4JG2, 4JH1, C223, C24SE, and 4ZE1.
• Alternative Market Coverage Verified: Confirmed for ISUZU KB VI (TFR, TFS) and Holden/Rodeo platform siblings in Australasian and European catalogs.
• Quality Certification: ISO9001 certification confirmed by multiple supplier listings for the 8-94172420-0 aluminum housing.
• Net Weight Not Publicly Disclosed: Public listings for this exact housing do not publish a net weight. Dorman's reference weight for the 902-5064 housing assembly is available only as a packaging specification. Confirm net weight at inquiry for freight planning.

• Coolant leak at the thermostat housing joint: Visible drips, dampness, or crusty residue (white/pink coolant crust) around the housing-to-cylinder-head interface or the housing-to-hose neck — the most direct sign of a failed gasket or a warped/corroded housing sealing surface.
• Overheating or temperature fluctuation: A housing that does not seal correctly allows coolant loss or air ingress, disrupting thermostat operation and causing temperature instability, especially under load or in stop-and-go driving.
• Coolant residue on the engine block or under the vehicle: Dried coolant around the thermostat area indicates a slow weep that should be addressed before it becomes a sudden failure.
• Visible corrosion or pitting on the housing sealing surface: Aluminum housings can corrode at the coolant passage edges, preventing the gasket from sealing even when new.
• Cracked or deformed housing: Impact damage or over-torqueing of the mounting bolts can crack the aluminum casting, requiring replacement.
• Thermostat not seating properly: A distorted housing cavity can prevent the thermostat from sealing, causing continuous coolant bypass and extended warm-up times.
• Repeated coolant loss without an obvious external leak: A compromised housing joint can allow coolant to seep slowly, producing unexplained reservoir level drops.

• 8-94172420-0 (“-0” suffix) vs. 8-94172-420-1 (“-1” suffix): The “-1” suffix is specifically cataloged as “PIPE; WATER OUTLET” in ISUZU TFR/TFS parts diagrams, while the “-0” suffix is marketed as the “Thermostat Housing Cap” with the integrated coolant outlet. They belong to the same functional family but are not always stamped with the same last digit. Compare the original unit's casting number or physical shape (presence of a thermostat cavity and outlet neck) before ordering.
• LHD vs. RHD: The same housing reference covers both LHD and RHD TFR/TFS applications. Confirm the chassis code and market configuration before ordering.
• Gasket inclusion varies: Dorman's reference housing includes a gasket, but not all aftermarket 8-94172420-0 listings include one. Confirm gasket inclusion at inquiry — a missing gasket means the vehicle cannot be returned to service until one is sourced.
• Aluminum sealing surface: Aluminum housings are sensitive to over-torqueing. Uneven or excessive bolt torque distorts the sealing flange and causes leaks. Use a torque wrench and follow the workshop manual sequence.

1. Confirm the required component first: Verify that the original unit is the housing with thermostat cavity and outlet neck, not a separate water outlet pipe. Compare the casting number and physical shape.
2. Cold engine only: Allow the engine to cool fully before opening the cooling system. Drain coolant to a level below the thermostat housing.
3. Remove the old housing: Disconnect the radiator hose from the outlet neck. Unbolt the housing from the cylinder head or intake manifold. Note the orientation and the position of the thermostat.
4. Clean the mating surface: Remove all old gasket residue and corrosion from the cylinder head face and the housing sealing surface. A clean, flat surface is essential for a leak-free seal.
5. Inspect the thermostat: Check the thermostat for correct operation. Replace if stuck open or closed. Confirm the correct temperature rating (82°C or 85°C per application).
6. Install the new housing with gasket: Seat a new gasket (included in some references, not all) on the cylinder head, position the housing, and insert the mounting bolts.
7. Torque in sequence: Tighten the housing bolts evenly in a cross pattern to the workshop manual specification. Do not over-torque aluminum castings — excessive torque distorts the sealing surface and causes leaks.
8. Reconnect the radiator hose: Reconnect the upper radiator hose to the housing outlet neck. Tighten the clamp securely.
9. Refill and bleed coolant: Refill with the correct coolant mixture and bleed the system according to the ISUZU procedure. Air pockets are a leading cause of post-replacement overheating.
10. Run and verify: Start the engine, bring it to operating temperature, and check for leaks at the housing joint and hose connection. Confirm the temperature gauge stabilizes and the heater blows hot.

• Inspect the housing joint at every coolant service or every 20,000–30,000 km — look for crusty residue or dampness.
• Replace the gasket whenever the housing is removed — gaskets are single-use compression seals.
• Flush coolant according to the manufacturer interval. Degraded coolant accelerates aluminum corrosion.
• Replace the housing if the sealing surface is pitted or warped — resurfacing an aluminum housing is not recommended for this application.

• Standard packing: Neutral carton with protective wrapping; bulk export pallet available.
• Package contents: 1 × Thermostat Housing. Gasket inclusion varies — confirm at inquiry (Dorman reference includes gasket; other aftermarket suppliers may not). Thermostat and mounting bolts are not included.
• Set options: Housing only / housing + gasket set — specify at inquiry.
• Suitable for: ISUZU TFR/TFS/Campo pickup cooling-system repair shops, 4JA1/4JB1 engine rebuilders, light commercial fleet maintenance departments, spare parts distributors, and export wholesalers serving Southeast Asia, the Middle East, Africa, and Latin America.
• Related parts available: Thermostat (8-97361-770-0, 82°C), housing gasket (confirm part number for specific application), upper radiator hose, water outlet pipe (8-94172-420-1), and complete 4JA1/4JB1 cooling-system kits.