Thermostats & Cooling Components - Marine Engine Parts
Marine Thermostats & Cooling Components
Marine Thermostats, Pumps, Impellers, Heat Exchangers, Hoses & Cooling Parts
Shop marine cooling system parts for inboard, sterndrive, outboard, gas, and diesel engines. Find thermostats, thermostat housings, raw-water pumps, circulation pumps, impellers, heat exchangers, oil coolers, strainers, coolant caps, hoses, clamps, gaskets, seals, temperature senders, and cooling service parts.
Match cooling parts by engine brand, model, serial number, existing part number, cooling layout, hose size, thermostat temperature, and pump style.
Overheating can come from more than one part. Check the full cooling path before assuming a thermostat, pump, impeller, hose, strainer, or heat exchanger is the only issue.
Top OEM Cooling Searches
Find Cooling Parts Faster
Search by Part Number, Engine Model, Temperature, Hose Size, or Cooling Symptom
Use the search box for thermostats, thermostat housings, raw-water pumps, circulation pumps, impellers, coolers, hoses, clamps, strainers, caps, seals, senders, and cooling kits.
Popular Cooling Product Searches
Raw-Water Side
Seawater Flow Protects the Engine and Exhaust
Raw-water systems depend on a clean intake path, healthy impeller, strong pump, good hoses, clear strainers, clean coolers, and proper exhaust water flow. Weak seawater flow can cause overheating quickly.
Closed Cooling
Thermostats, Coolant, and Heat Exchangers Control Temperature
Closed-cooling systems depend on the right coolant, thermostat, circulation pump, pressure cap, heat exchanger, hoses, seals, and clean passages to keep engine temperature stable.
Control Temperature
Thermostats, senders, pumps, coolant, caps, and heat exchangers all affect stable operating temperature.
Protect Water Flow
Impellers, strainers, hoses, clamps, pump covers, and coolers should be inspected when flow seems weak.
Replace Seals Carefully
Use the correct gaskets, O-rings, washers, caps, and clamps when cooling parts are opened.
Cooling Service Help
Overheating Usually Deserves a Full-System Look
Replacing one part may not solve a cooling issue if the root cause is a clogged strainer, worn impeller, failing thermostat, soft hose, leaking cap, weak pump, blocked heat exchanger, air leak, or exhaust restriction.
Related Engine Service Parts
Complete the Cooling System Service
Cooling Components FAQ
Choosing Marine Thermostats and Cooling Parts
How do I find the right marine thermostat?
Start with the engine brand, model, serial number, current thermostat part number, thermostat temperature rating, and housing style. Similar thermostats may not fit or operate correctly.
What causes a marine engine to overheat?
Common causes include worn impellers, clogged strainers, blocked heat exchangers, failing thermostats, soft hoses, weak pumps, low coolant, exhaust restrictions, or air leaks on the intake side.
Should gaskets and O-rings be replaced during cooling service?
Yes. When opening cooling components, use the correct replacement gaskets, O-rings, washers, seals, and clamps for the part and engine model.
Can the Parts Desk help identify cooling parts?
Yes. Send the engine brand, model, serial number, photos of the part, hose diameter, old part numbers, and the symptom you are trying to solve.
Shop Marine Thermostats, Pumps, Impellers, Heat Exchangers, Hoses & Cooling Parts
Find the cooling components and service parts needed to keep marine engines flowing properly and running at the right temperature.
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PCM Thermostat 170°F Closed Cooling – R026007
The PCM R026007 Thermostat is a genuine OEM 170°F thermostat designed specifically for fresh water cooled (closed cooling) PCM and Crusader marine ...
View full detailsPCM Thermostat Kit 143°F – RP026002E
The PCM RP026002E Thermostat Kit is a genuine OEM 143°F raw water thermostat designed for Pleasurecraft Marine (PCM) Ford-based inboard engines. Th...
View full detailsYanmar Marine Engine Thermostat - OEM Cooling System Component
OEM Thermostat for Yanmar Marine Engines This genuine Yanmar thermostat is designed for marine engines, regulating coolant temperature to maintain ...
View full detailsVolvo Penta Thermostat Kit – 3831426
The Volvo Penta 3831426 Thermostat Kit is a genuine OEM cooling system service kit designed to regulate engine temperature and maintain optimal per...
View full detailsMercury MerCruiser Quicksilver Thermostat Assembly 8M0174561
Mercury MerCruiser / Quicksilver Thermostat Assembly – 8M0174561 Maintain proper engine cooling and operating temperature with the genuine Mercury ...
View full detailsCrusader Thermostat 143°F | OEM Raw Water Cooling | Part R026002E
Crusader Thermostat 143°F — OEM Part R026002E Genuine Crusader OEM 143°F (62°C) thermostat for raw water cooled Crusader and PCM inboard marine en...
View full detailsMercury MerCruiser Quicksilver Thermostat Sleeve 8M0214947
Mercury MerCruiser Thermostat Sleeve 8M0214947 Part Number: 8M0214947 (service format: 23-8M0214947) Brand: Mercury / Quicksilver Product Type: Th...
View full detailsMerCruiser 864509 Cooling Hose – Thermostat Housing to Lower Manifold
MerCruiser 864509 – Molded Cooling Hose | Thermostat Housing to Lower Exhaust Manifold Part Number: 864509 | Reference: 32-864509 Brand: Mercury...
View full detailsMerCruiser 864539 Cooling Hose – Thermostat Housing to Starboard Manifold
MerCruiser 864539 – Molded Cooling Hose | Thermostat Housing to Upper Starboard Manifold Part Number: 864539 | Reference: 32-864539 Brand: Mercu...
View full detailsMercury MerCruiser 864579 Cooling System Hose – Check Valve to Thermostat Housing
Mercury MerCruiser 864579 – Cooling System Hose Part Number: 864579 / 32-864579 Brand: Mercury / MerCruiser Type: Molded cooling-system hose Posi...
View full detailsMercury Quicksilver Thermostat 8M0139434 — 125°F | 15 & 20 HP EFI FourStroke
Mercury Quicksilver Thermostat — OEM 8M0139434 | 125°F | 15 & 20 HP EFI FourStrokeThis genuine OEM thermostat regulates cooling-water flow on s...
View full detailsMercury Quicksilver Thermostat 130°F – 8M0057307
Mercury Quicksilver Thermostat 130°F — 3.0L V6 OptiMax Outboard Part Number: 8M0057307 | GTIN: 745061562318 Brand: Mercury / Quicksilver | Tem...
View full detailsHeater Craft Complete Shower System with S102 Thermostatic Valve | 760-101SC
Complete Marine Shower System with Thermostatic Valve ControlThis all-in-one marine shower kit gives you a fully functional hot-water shower aboard...
View full detailsPCM 160°F Thermostat with 156-Hole Housing 97895
PCM 160°F Thermostat with 156-Hole HousingKeep your PCM inboard engine running at its optimal operating temperature with this OEM-spec 160°F thermo...
View full detailsSierra Thermostat — Kohler Marine Engines — 47-233608
Sierra Thermostat — Kohler Marine Engines — 47-233608 A direct-fit replacement thermostat for compatible Kohler marine engines. The thermostat regu...
View full detailsRaritan WH16 Thermostat Assembly — Marine Water Heater Replacement Part (78-WH16)
OEM Thermostat Assembly for Raritan Marine Water HeatersThe Raritan WH16 Thermostat Assembly (78-WH16) is the factory replacement thermostat for Ra...
View full detailsJabsco 6-Hole Pump End Cover Plate - JAB-11831-0000
The Jabsco 11831-0000 Pump End Cover Plate is a replacement end cover for compatible Jabsco flexible impeller engine-cooling pumps. This 6-hole cov...
View full detailsMercury - Water Distributor Thermostat Housing Gasket - 27-475901
The Mercury MerCruiser Quicksilver 27-475901 Gasket is an OEM cooling-system sealing gasket used on select Mercury MerCruiser sterndrive engines. I...
View full detailsKasco 120350 C20 De-Icer Timer, Thermostat and Controller
Overview Time and temperature controller for de-icers that lets you set when the de-icer activates based on temperature and time of day. Operates b...
View full detailsKasco 110225 C10 De-Icer Thermostat and Controller
Overview Kasco 110225 C10 De-Icer Thermostat and Controller The C-10 controller uses an adjustable air temperature thermostat to turn the de-icer ...
View full detailsSierra - Water Temperature Sender Dual Station 3/8"-18 NPT - SIE-18-5897
The Sierra Marine 18-5897 Water Temperature Sender is a dual-station marine engine temperature sending unit for compatible inboard and sterndrive g...
View full detailsVolvo Penta - Charge Air Cooler Thermostat Kit - 3588437
The Volvo Penta 3588437 is a genuine OEM charge air cooler thermostat kit used on select Volvo Penta D4 and D6 marine diesel engines. This kit serv...
View full detailsMercury MerCruiser Quicksilver Thermostat Cover Gasket 62386001
Thermostat Cover Gasket — OEM Reference 62386001 / 27-62386001 Part Number: 62386001 | Service format: 27-62386001 Brand: Mercury Marine / Quicksi...
View full detailsMercury MerCruiser Quicksilver Thermostat Housing Gasket 806871
Mercury MerCruiser Thermostat Housing Gasket 806871 Part Number: 806871 (service format: 27-806871) Brand: Mercury / Quicksilver Product Type: The...
View full detailsMercury Thermostat Cover Gasket 14318005
Mercury 14318005 is a genuine OEM thermostat cover gasket for select Mercury and Mariner 2-stroke outboards. Current Mercury dealer references iden...
View full detailsMercury MerCruiser Thermostat Retainer 861949T
Mercury MerCruiser Quicksilver 861949T is a genuine OEM thermostat retainer used in MerCruiser big-block cooling-system assemblies. Current Mercury...
View full detailsVolvo Penta Thermostat Housing 21967279
Volvo Penta 21967279 is an OEM thermostat housing used in the engine coolant circuit. The housing provides the mounting and coolant-routing locatio...
View full detailsVolvo Penta Thermostat O-Ring 3586514 | D1 D2 D8 D9 D11 Diesel Cooling
Part Details Part Number: 3586514 Brand: Volvo Penta Type: O-ring — thermostat / heat-exchanger cooling-system seal System: Cooling — thermost...
View full detailsVolvo Penta Thermostat Cooling O-Ring 3583830
Volvo Penta 3583830 is a genuine OEM O-ring used in Volvo Penta cooling-system service. Current fitment trails support this seal in compact Volvo P...
View full detailsPCM Pump-to-Thermostat Housing Elbow – R024002
he PCM R024002 is a genuine OEM pump-to-thermostat housing elbow used in Pleasurecraft Marine (PCM) fresh water cooling (FWC) systems. This compone...
View full detailsVolvo Penta Thermostat Housing Gasket – 1542123
Product Title Volvo Penta Gasket 1542123 – OEM Marine Engine Thermostat Housing Gasket Product Description The Volvo Penta 1542123 Gasket i...
View full detailsPCM Thermostat Housing Gasket RM0004
Prevent coolant leaks and maintain proper engine cooling with the PCM Thermostat Housing Gasket RM0004. This genuine Pleasurecraft Marine (PCM) OEM...
View full detailsMerCruiser Thermostat Cover Housing – 8M0061068 (454 / 502 Big Block)
The Mercury / Quicksilver 8M0061068 Thermostat Cover Housing is a genuine OEM upper thermostat housing cover used on MerCruiser GM-based marine eng...
View full detailsVolvo Penta Thermostat Housing 3583098 | KAD42 KAD43 KAD44 KAD300 OEM
Volvo Penta Thermostat Housing – 3583098 Part Information Part Number: 3583098 Brand: Volvo Penta Official Product Type: Thermostat Housing O...
View full detailsYanmar Thermostat Gasket 129150-49811 - Marine Diesel Engine
Genuine Yanmar Thermostat Gasket - Professional Marine Engine Component OEM thermostat gasket designed for Yanmar marine diesel engines. Precision-...
View full detailsYanmar Thermostat Gasket 119773-49570 - Marine Diesel Engine
Genuine Yanmar Thermostat Gasket - Professional Marine Engine Component OEM thermostat gasket designed for Yanmar marine diesel engines. Precision...
View full detailsYanmar Thermostat 119773-49550 - 70°C Marine Diesel Engine
Genuine Yanmar 70°C Thermostat - Professional Marine Diesel Engine Component OEM thermostat designed for Yanmar marine diesel engines with a 70°C ...
View full detailsYamaha Thermostat 6H3-12411-20-00 - Special Order
The Yamaha 6H3-12411-20-00 is an OEM thermostat for select Yamaha two-stroke outboard cooling systems. It regulates engine operating temperature by...
View full detailsYamaha Outboard Thermostat – 6AW-12411-00-00
The Yamaha 6AW-12411-00-00 Thermostat is a genuine OEM cooling system component designed to regulate engine temperature in Yamaha outboard motors. ...
View full detailsYamaha Thermostat Seal | 67F-12412-00-00
Genuine Yamaha OEM thermostat seal designed to provide a reliable, leak-free seal in your marine engine's cooling system. This precision-engineered...
View full detailsYamaha Outboard Thermostat – 67F-12411-01-00
The Yamaha 67F-12411-01-00 Thermostat is a genuine OEM cooling system component designed to regulate engine temperature in Yamaha outboard motors. ...
View full detailsSierra Marine Thermostat 18-43017 – Indmar S985009 / MerCruiser 8.1L 496 MAG Cooling System
The Sierra 18-43017 Thermostat is a precision 160° temperature control thermostat designed for high-horsepower GM-based marine engines, including I...
View full detailsSierra 18-3552 Thermostat – Mercury MerCruiser Replacement
The Sierra 18-3552 Thermostat is a high-quality aftermarket replacement designed for Mercury MerCruiser engines, providing reliable temperature reg...
View full detailsSierra 18-3549 Thermostat 120°F – Johnson Evinrude OMC Replacement
The Sierra 18-3549 Thermostat (120°F) is a premium aftermarket replacement designed for Johnson, Evinrude, and OMC outboard engines. It regulates e...
View full detailsVolvo Penta Thermostat Kit – 875580
The Volvo Penta 875580 Thermostat Kit is a genuine OEM cooling system service kit designed to maintain proper engine operating temperature in Volvo...
View full detailsVolvo Penta Thermostat – 8149182
The Volvo Penta 8149182 Thermostat is a genuine OEM cooling system component designed to regulate engine temperature in Volvo Penta marine diesel e...
View full detailsVolvo Penta Thermostat 3856961
The Volvo Penta 3856961 Thermostat is a genuine OEM cooling system component designed to precisely regulate engine temperature in Volvo Penta marin...
View full detailsVolvo Penta Thermostat 3842015
Volvo Penta 3842015 is a genuine OEM engine thermostat used in Volvo Penta compact marine diesel cooling systems. Current Volvo Penta dealer refere...
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